how interested your post is... why dont you google yourself about the differences in there.
i am an employee at wireless company for over 14 yrs. i dont need to explain you my details, but allow me to give u some briefs....
cingular does allow any cingular users to to use their mobiles/PDAs in other 200 countries because they have same networks - GSM, GPRS, EDGE, and HSDPA as well as tmobile, however, what tmobile doesnt have in USA is HSDPA which is 3G. from what i heard cingular will have HSDPA in 60 cities at end of 2006. Tmobile hasnt started HSDPA yet.
also, as cingular user, you can use the mobiles on cruise ships such as celebrity, royal carribeans and other cruise lines.
i traveled to south america with my sk2 for 2 wks last march. sk2 sucked big time. i went crazy not to have emails or internets...
any mobile user under tmobile or cingular or other wireless company with GSM/EDGE/3G can travel to other countries with their mobiles. it depends on what mobile has quadband EDGE/GPRS and Tri-band HSDPA/3G UMTS.
beware: verizon and sprint users might be hard to find the high speed network in other countries that match with their networks... EVDO/CDMA networks are very few in world.
Cingular will throw GSM network this coming winter. also cingular will throw TDMA network next yr. that is what i heard.
