I'm a canadian so i use Fido all the time.
But I'm touring the states for a month though, so I went over the border today to a t-mobile store and got a SIM card and the total internet plan. I told them I was using my iphone 2G and it was already unlocked.

So apparently I have to enter an APN/username/password for it to work. I've searched a bit and i see some people using internet2.voicestream.com, epc.tmobile.com...

Which one should I use? Whats the difference? And what is my username and password for the APN network??
Thanks, and sorry for this question already being answered hundreds of times (I'm sure).

i use epc.tmobile.com beacause it doesn't require any special files (some proxy file that us 2gers had to use a while back), though i've heard it doesn't work everywhere. I haven't personally had any problems in New Jersey