Stupid, Annoying, F%&^*ing QQ!!!
While it is so absolutely uncool to be a young, urban professional in one of China's main cities and still admit to using QQ instead of MSN (despite the fact that a large number of those same individuals in fact DO use QQ), I will come out and admit to using it on a regular basis (when I can actually sign on to it). For those who are unaware of QQ, you must either be outside of China or under a rock, because its by far the most popular chat software in China with huge market penetration, a major place in China's modern culture, and has even led to a spin off clothing line.
Unfortunately, as a Mac user, using QQ is not so easy. Tencent has yet to release a version of QQ that can be used by Mac users. Instead, those who are mac users and still hope to use QQ have a few choses, iQQ, LumaQQ, and Adium. LumaQQ is probably the best choice, though with Adium you can run both QQ and MSN. According to some, if Tencent and Mac teamed up to come out with a QQ version, Apple would instantly become far more popular in China.
For those in China who are Mac users, especially those who have computer problems, you may want to check out this post (as well as the comments) from Danwei, recommending places to go in Beijing, as well as Shenzhen, for fixing a Mac.