I have T-Mobile. I have a PC card and unlimited internet for $20 a month with an existing voice account, otherwise it is $30 a month stand alone. I think the wireless card was around $300. Works OK, usually at dialup speeds, sometimes slower, sometimes faster. I have found that it only works within T-Mobile areas. Voice works while roaming on other GSM networks, but no go on the data while roaming.
Shelby