Unlocked iPhone 3Gs Can Multitask

Just FWIW: I was in the local Apple Store a few days ago biding my time while I wait for the white iPhone 4s to finally come out. I chanced upon a fellow with an unlocked iPhone 3G talking on Verizon, and he demonstrated performing Multitasking on it. So, apparently it's not strictly a hardware issue, and there's some sort of AT&T connection involved.