Hey, I have an alternate solution. Just get your Blackberry unlocked by the service provider. Buy a SIM card in Asia for whatever country you are in and use their SIM card and number. Most of the Asian companies are prepaid and cheap! You can usually buy a SIM card for about $2-3, get some prepaid load (maybe $10) and avoid all those nasty roaming charges from your carrier.
Also, Asians love texting and Blackberry is supreme for texting.
It's worked for me in Hong Kong, the Philippines, and Indonesia on my Blackberry 7290, and 7230 before that.