My friend just gave me his old iPhone 3G to replace my Palm Pixi (AT&T). After putting the SIM in the iPhone, calling and texting work, but trying to use data in Safari, the App Store, etc, I get a message that says "Could Not Activate Cellular Data..." and that I don't have a data plan. Thing is, I did have a plan with the Palm phone, it was a 200mb/month deal. The Wifi also doesn't work on the iPhone, it can't find any networks. Anyone know how to solve this problem?