I was reading a Foreign Policy article about the Chinese government's "deep suspicion of social media and the Internet" which included a link to a very interesting presentation about Sina Weibo - one of several Chinese answers to Twitter.
Founded in August 2009, Sina Weibo had 80-100 million users by the end of 2010. The author of the presentation, Bill Bishop, suggests it is superior to Twitter.
For starters, you can say far more in 140 Chinese characters than you can using other alphabets. I'm afraid I wouldn't be able to benefit from this feature but I could certainly see the value of adding a "search what people you follow have said" button to Twitter.
And there are some other interesting bells and whistles including groups and events.
Bishop says: "It is a better designed and more stable product, and Sina’s product roadmap appears to have it heading towards a robust SNS, almost like Facebook."