The below is an interesting post I found in regards to worldwide social media usage:Facebook is breathing down Orkut’s neck in Brazil. But that’s not all, Twitter is also becoming a strong contender too.According to data compiled by comScore, the ratio of Brazilian Twitter / Internet users suggested that the micro-blogging site is very popular among the population. This Brazil mini case reflected how the world, in general, has chosen Twitter and Facebook as its finalized choices of online social networking sites.The largest market left untouched would be China, where RenRen currently dominates. Zuckerberg’s vision to make the world more open can be realized if China were to remove its firewall. With internal and external pressure building up (Prisoner and Nobel Peace Prize winner, Liu Xiao Bo as the latest case) China may one day loosen its grip.But when is the question. Maybe in 10 or 20 years time?