I have a new 3GS and just signed up with ATT.. unfortunately for me, there are two available antennas in range of my house.. the one which seems to have first priority only provides 1 bar of signal (no 3G).. so little signal that practically every call fails.. sometimes my phone will pick up on a second (lower priority) antenna which gives me full 5 bars with 3G and all is well.. but i'll be on a call, then the phone decides to switch over to the bad signal antenna again and my call drops..
I understand that this is something that ATT locks out via the SIM.. I had a hack for my Palm Treo to allow manual network selection which worked GREAT.. I'd just select the "good" antenna and all was well. This was here:
GadgeTech.info - Information and Reviews
Does this same hack exist for the iPhone? Unfortunately unlocking the phone still doesn't provide this functionality.. unlocking still just shows a single instance of "Automatic" or "ATT" (versus multiple options).
If anybody would be willing to develop such a hack, I'd gladly donate for the effort. Thanks!