iTether, which enjoyed a few hours in the App Store this week, allowed the iPhone to become a portable modem, feeding Internet service to any laptop through a USB cable. For a one-time fee of $15, iTether was a steal compared to the $20 per month charged by AT&T and Verizon and the $30 per month charged by Sprint.
Violation: Carriers forbid unauthorized tethering in their terms of service, so iTether was never going to last.
Jailbreak Alternative: MiWi or PDANet should do the trick.
(MORE: AT&T Cracks Down on Unofficial Tethering)