After a few terrible years for IPOs, some exciting technology companies look like they’re ready to step up to the IPO plate in 2011 or 2012. Here’s an unofficial list of 23 tech companies that – according to rumors from the Wall Street Journal and TechRice among other sources – might go to market this year or next:

58.com IPO? China’s for-profit version of Craigslist.org, 58.com’s got a robust user base. A recent browse through the site’s classified ads in Beijing showed more than 1.2 million listings for people looking for roommates – and that’s just in one city! The site ranks 34th in online traffic in China, according to Alexa.com.

360buy.com IPO? The third-largest online retailer in China, 360buy.com just secured a nice chunk of change from Wal-Mart. They got more than $500 million in all. As I wrote previously, 360buy.com controls 2.5 percent of the e-commerce market in China. That may not sound like much, but that’s more than 3.5 times the e-commerce marketshare enjoyed by competitor China Dangdang, Inc. (NYSE:DANG).

Demand Media IPO? A content factory that uses an army of freelancers to churn out “How To” articles, Demand Media has turned the written word into a commodity on eHow.com. All told, eHow produces enough text to fill more than four English language Wikipedia’s every single year. And their so-called “evergreen” articles aren’t pegged to specific dates, so they’ve got a very long shelf-life of search-engine friendly content that’s perfectly suited for advertisements.

Update: Demand Media IPO’d on Jan. 26, 2011 under ticker symbol DMD. Check out my latest post on the company: Will Demand Media’s (DMD) stock recover from Google shock? Absolutely.

Facebook IPO? I can’t say much that hasn’t already been said about Facebook, except this: they’re the only Web-based company in U.S. that’s positioned to truly challenge Google in the coming years. As they expand into search, virtual goods, e-commerce and mobile, Facebook seems to be taking over the internet. Indeed, the site currently accounts for 25 percent of ALL pageviews in the U.S. Even with a $75 billion+ valuation, Facebook still looks cheap to me.

Groupon IPO? Groupon’s found the holy grail of online marketing: a simply way to marry coupons and local businesses. To use it, just give Groupon your email address and they send you a daily offer from a local business. If you like the offer (which is often a coupon or gift card that’ll save you 50 percent or more at a local restaurant, hobby shop, etc.), you can buy the coupon, print it out and redeem it anytime before the expiry date. The company’s already rejected a $6 billion buyout offer from Google, and they’re in the early stages of expanding into China. The only problem? Google’s got Groupon on their hit list now, and an all-out war is probably in the making.

Hulu.com? A streaming video site with backing from media heavyweights like News Corp. (NASDAQ:NWSA), Walt Disney (NYSE:DIS), and NBC Universal, Hulu claims to be operating at a profit with 2010 revenues around $260 million. The company’s biggest competitor is streaming giant Netflix, Inc. (NASDAQ:NFLX), which now has a market cap of $9.6 billion.

Jiayuan IPO? The leading online dating site in China, Jiayuan’s the 55th most-visited site in China, and it boasts at least 25 million members. The company makes money by charging for memberships (about $6 a month for a “Diamond Membership”), selling virtual currency and other romantic add-ons. Jiayuan has attracted capital from New Oriental Education & Technology Group (NYSE: EDU) among other investors.

Update: Jiayuan shares started trading on May 12, 2011 under ticker “DATE” on the NASDAQ. Check out my latest post on the company: Jiayuan.com IPO: 3 reasons to invest in Chinese dating site.

LinkedIn IPO? A social networking site for professionals, LinkedIn boasts more than 90 million members from around the world. The company lacks the sex appeal of some of the other tech IPOs on the docket, but it does seem like its network might be easier to monetize than, say, Twitter, since it can capitalize on hiring solutions, advertising aimed at professionals and premium landing pages.

Update: LinkedIn IPO’d on May 19, 2011 under ticker symbol “LNKD.” Check out my latest post on the company: 3 reasons NOT to invest in LinkedIn IPO.

LivingSocial IPO? The biggest and most well-known Groupon competitor, LivingSocial offers daily deals from local and national retailers. LivingSocial got a big boost when it announced that Amazon.com, Inc. (NASDAQ:AMZN) was investing $175 million in the company. Soon after, LivingSocial offered its members a $20 Amazon gift card for just $10, and they netted both companies more than $13 million up front in the deal.

Nuomi IPO? An ultra-deep discount coupon site, Nuomi’s fighting for attention in what will soon be a very crowded market. Still, they’ve got decent ownership in Oak Pacific – the parent company of “China’s Facebook”: RenRen. And they’ve got a decent idea: do as Groupon does. The company sells coupons online for a limited time. At least one theater owner who partnered with Nuomi was thrilled with the results: “I’d say this is a miracle,” producer Lei Zile told the Global Times last July. “I’ve talked to older producers about this and they all said it was a miracle in the history of stage plays. 100,000 tickets were sold in one day. You could call it encouraging.”

Pandora IPO? An online music streaming site, Pandora grew out of the Music Genome Project, which attempts to categorize music based on more than 400 variables. Using that information, Pandora can build “custom” radio stations after you’ve entered a song or band that you like. The site’s enjoyed a big surge in popularity with wider-spread adoption of smartphones that allow streaming music anywhere, anytime. Despite the fact that Pandora shelled out more than $30 million in royalties in 2009, the company still managed to make its first profit that year, netting some $50 million. In 2010, profits were estimated to be around $100 million largely on the strength of premium ad-free streaming accounts and partnerships with car manufacturers that are installing Pandora direct from the factory.

Qunar IPO? An online travel booking site in China, Qunar’s Web traffic is pacing Ctrip.com’s (NASDAQ:CTRP). Both companies operate in the same niche, but Ctrip’s more well known in the West since its IPO came in 2003. Since 2003, shares in Ctrip have risen more than 750 percent. Competition in the sector seems to be heating up as Tencent Holdings, Ltd. (HKG:0700) recently invested in 17u.com, another Chinese travel site that’s currently a distant third behind Ctrip and Qunar.

Renren IPO? A glaring example of the copyright issues that plague China, when RenRen.com launched in 2005 as XiaoNei.com, the site looked like it was an official Facebook product. It even identified itself as “A Mark Zuckerberg Production” at the bottom of its pages. After getting bought out by Oak Pacific Interactive in 2006, the company’s since tried to carve its own niche – and its done well. RenRen.com currently has more than 160 million registered users in China, and it’s the country’s 16th most-visited site.

Update: RenRen went public on May 5, 2011. Shares have collapsed more than 30 percent since then. Check out my latest post on RENN: RenRen IPO: 5 things you don’t know about ‘China’s Facebook.’

Sunity IPO? A Chinese version of Zynga, Sunity Online Entertainment Ltd. makes Web-based games and will soon start launching mobile apps, according to the AP. The company racked up $9.54 million in revenue in 2010, up from $8.25 million in 2009. Sunity generates 52 percent of its revenue from Qihang (QHG) – a subscription-based cards and chess game, according to Gaming-Hub.com. Another 8 percent of the company’s revenue comes from Han Dynasty Game (HDG) – a free Chinese mythology role-playing game that makes money off the sale of virtual goods.

Skype IPO? Skype’s VoIP services offer businesses and individuals a free or low-cost way to make international calls, host video conferences and shares files online. With the company’s recent $100 million acquisition of mobile video streaming service Qik, it’s clear Skype’s getting aggressive about making a push into the smartphone market.

Update: Microsoft acquired Skype on May 10, 2011 for $8.5 billion.

Taobao IPO? It’s unclear whether or not Taobao will IPO in 2011 or 2012, but it is, hands down, my favorite stock on this list. Taobao controls 75 percent of the e-commerce market in China with it’s psuedo-eBay-style site. There, consumers can buy products from other consumers or businesses at auction or at set prices, although auction-style buying seems to have fallen out of favor on the site. Credit Suisse analysts expect the e-commerce market to more than quadruple in China by 2015, and Taobao will easily be the biggest beneficiary of those gains. They seem to have seen the writing on the wall, too, as the company’s investing $3 billion to $4.5 billion into a warehouse network that will make shipping throughout China more efficient.

Taomee’s 61.com IPO? A Chinese social networking site aimed at children and parents, 61.com has some 20 million users ages 6 to 14, and Forbes reported revenue projections of more than $30 million in 2010. The subscription-based site lets kids hang out in virtual worlds (the Seers for the boys and the Moles for mixed-gender users), and parents are invited, too.

Tudou IPO? While they may be playing second fiddle to Youku.com, Inc. (NYSE:YOKU), video streaming site Tudou.com gets nearly as much traffic. The site’s ranked by Alexa.com as the 11th most-visited Web site in China. Youku.com’s ranked as the 10th most-visited site. Youku’s spectacular November IPO could foreshadow another buying frenzy in Tudou even though its unclear when or how either company will get profitable.

Update: Despite an ongoing legal battle between Tudou’s CEO and his ex-wife, the company appears to be moving closer and closer to an IPO. Check out my latest post on the company: Tudou IPO: Is Tudou stock a buy?

Twitter IPO? Microblogging site Twitter still isn’t profitable, but it looks like it’s getting serious about making money after staggering valuations put the company’s market cap around $3.7 billion. Twitter appointed its former COO Dick Costolo as CEO late last year, and Costolo’s tasked with ramping up revenues. A report out yesterday by online research firm e-Marketer Inc. estimates the company will generate $150 million in ad revenues in 2011 and $250 million by 2012. I’ve also blogged in the past about what I see as Twitter’s secret key to making money.

VANCL IPO? An up-and-coming online clothing retailer in China, Vancl.com’s got excellent pedigree in site founder Chen Nian who sold his last project, Joyo.cn, to Amazon. Vancl.com’s focus on clothing has helped it capture nearly 30 percent of all online clothing sales in China, and the company expects its warehouse space to triple by the end of the year. Last year’s sales at Vancl were expected to be up more than 300 percent, according Businessweek.com.

Yandex IPO? My second-favorite stock on this list, Yandex.ru is likely among the least well-known of the stocks, too. Expect to hear a lot more about Yandex if the company IPOs on the NASDAQ. The leading search engine site in Russia, Yandex claims revenue spiked by 43 percent to $410 million last year. Google holds the No. 2 slot in Russian search engine usage and the American search company posted revenue of some $69 million in Russia in 2009. Yandex.ru is the most-visited site in Russia and the 25th most-visited site in the world, per Alexa.

Update: Yandex IPO’d on May 24, 2011. Check out my latest: Yandex IPO: 5 reasons to invest in Yandex stock.

Zhenai IPO? A Chinese dating site, Zhenai.com claims more than 26 million registrations as of August 2010. While the site gets far less traffic than its biggest competitor Jiayuan, Zhenai adds a human touch to the matchmaking process by having trained matchmakers help users find the best possible matches.

Zynga IPO? An online game maker, Zynga’s most famous for its iPhone and Facebook apps Farmville and Cityville. The company boasts a market cap of $5.8 billion on SharesPost. Sound like a lot? At least Zynga’s not having much trouble making money. Zynga likely generated revenue of more than $500 million last year, Lou Kerner, an analyst at Wedbush Securities, tells Dealbook. That’s up from about $300 million in 2009. That’s not bad, especially since Kerner estimates the company has profit margins of some 20 percent.

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