Close, but not entirely correct. GSM phones are prevalent in Europe and
Australia. There are around 4 or more GSM phone networks in the US, e.g.,
Omnipoint, but not many and coverage is limited. Omnipoint can move your SIM
chip to a GSM phone that will work in Europe. My friends from England move
their SIM chip to an Omnipoint US phone when in the US. The US uses either
CDMA or TDMA which as yet is not compatible with GSM. However, hopefully
this summer Nokia and some others will introduce for public consumption a
technology which allows bridging between GSM and the CDMA and TDMA systems.
That would be a godsend for those of us who would like to bring our US
phones to Europe. Finally, AT&T will provide you with a phone for use in
Europe that uses your US number. Unfortunately, once you pay AT&T's rates
you start running out of assets.