Well I havent contributed for sometime so its nice to do so. Got the same problem for my team and myself when we visit the states in April for the RSA show. The answer is
http://www.wireless.att.com and the gophone payugo solution. You can purchase 100mb of data for $20. Expensive by european terms but the best the US market offers. I took delivery this morning of 3 simcards (purchased from ebay) that I will activate online 7 days before we head out there - that way we can firstly qualify for the first recharge bonus and also circulate the phone numbers within the office and friends/wives/boyfriends.
Oh how I wish you could just bang in a tmobile uk sim card like we can and have unlimited pda access for 75c a day