Playing around with my Sprint iPhone 4S I stuck in an AT&T SIM card and watched the top go to searching... and as it did I went to about in general in settings and the carrier name had switched to AT&T! Then, I went to cellular and tapped on "set up personal hotspot." The phone said "please call AT&T at 611 to set up personal hotspot." That's so cool!!! What's going on and have I just found a hack?! What do you guys make of this?