No. The iPhone 3GS is sadly a GSM only phone, so it cannot function on Sprint (or Verizon's) bandwidths.
No because even if it is unlocked sprint works on a CDMA and AT&T works on a gsm signal it's like trying to use AM on FM radio only
Yes
Yes it does.
I tried it with my 3GS and it does work.
i am pretty sure at&t. more people have switched because of the iPhone3G and iPhone 3GS
Probably not, they have different exterior shapes.
iPhone 3GS
iPhone 3gs
the iphone 3gs replaced the iphone 3g.
Dose the iphone 3gs have a radio
If you mean,' Do iPhone 3GS's have Verizonservice?'No, not anymore, as of 17/10/2011 you can only get the iPhone 3GS on AT&T!
no why do you think its called trading in?