Just got back from a visit and needed to get a new phone # since my last had expired.
The excellent news was that the SMS spam that was arriving at several+ per day no longer showed up at the new number... Also agree that 1-2-Call had excellent voice coverage in most places. It got pretty spotty or completely dropped in the mountains near Myanmar between Pai and Mae Hong Son -- but that was more the location as my Cingular Blackberry with GPRS/EDGE and my Verizon phones all lost signal as well.
I have not used the phones for data calls -- should really read up on that as it sounds like a better solution than finding WLAN's or paying hotel prices for internet service.