Every couple months we see a new tethering app make its way into the App Store, before the plug is quickly pulled by Apple. Late last year, an app called iTether was a winner, but it was in there for only a few hours before Apple responded.
Now, the people behind iTether have revised their app, releasing it as an HTML 5 web app. This means that not only can you use this service without jailbreaking, but it is entirely outside of Apple’s control. They posted a video demo on how to do this:
The service costs $30 a year, so it is considerably cheaper than carrier tethering options. Check out this link for more info.