It's a slight shift of direction, but I travel with a bluetooth card (3com 3CRWB6096B) and a three-band GSM GPRS phone (Nokia 6310i) with a contract account with Vodafone and the result blows me away!
I have used it in many countries (admittedly all 1st World) and the results are excellent. It costs £4.30 a Mb, with no fixed charges, and runs at 56Kbps, the same as a domestic modem. It works on trains and boats.
It has cost about £100 in the first year.
Oh, and
BOAC I have nothing to do with any of the three companies, so this isn't advertising, it's just a ringing customer endorsement
Will