Go to a Chinese cell phone store in Vancouver or Richmond and you should be able to get your phone unlocked for $20~30.

CSL has probably the best coverage in HK and you can buy the prepaid SIM card at any 7-Eleven stores. Go to www.hkcsl.com for further details.

North American GSM phones operate on the 1900 frequency and you will need 900/1800 frequencies for most of the rest of the world. Make sure that your phone is capable of operating on all three frequencies. I also think S. Korea is different, but not sure. You can go to www.fido.ca to check.

In SIN, check out Singtel's Local Direct Dial service at http://home.singtel.com/consumer/pro...d_overview.asp using your home SIM card.