You can get the EDGE technology from T-Mobile, Verizon or Cingular and you don't have to buy their pc card. You can buy a sony ericsson GC83 with EDGE technology on Ebay. You just have to search for one that says UNLOCKED. We just got ours and signed up with T-Mobile. Their plan is only $29.95 and you get unlimited minutes. They also just got EDGE technology. You will get the faster service in areas where they have the EDGE already up and running, where it's not it will be comparable to dial up.
T-mobile does not currently sell a pc card that has EDGE technology so you have to buy it elsewhere. The sales people in their stores can set your pc card up with a SIM card and your good to go. Just make sure that if you order on ebay that it says it's UNLOCKED. We bought it from sunsunsun and got it yesterday. Last night we were surfing the net at faster speed than our desk top which is still on dial up. Seems to work great so far.