Originally Posted by
PTravel
Definitely buy a phone as described here. However, the OP should post in both the China and HK forums. Most SIM cards purchased in China won't work in Hong Kong and vice versa, i.e. the OP may need to buy one in each city.
Sure they do; you just need to activate roaming. FYI, China Mobile's roaming rates are quite reasonable when compared to other major telcos. In fact, when I'm in the US or Europe these days, I don't even bother picking up a local number any more.