If you signed up for contract-free iPhone service, you might have noticed some “Your last transaction cost $0.00″ messages. It’s hard not to. Sometimes twenty or thirty of them pile up at a time. As of today, it looks like AT&T has finally switched these useless messages off. It’s still to early to tell if all the last transaction messages are gone or only the free ones–I’m guessing the latter rather than the former. In any case, it’s a nice relief to be done of them. Good riddance.