Here is a nice and simple way of getting 30 free days of T-mobile Hotspot access, without any kind of commitment.

Signup for their "pay as you go" plan, and you’ll get to try it out for a month, and after that it will convert to a pay as you use plan without any monthly fee. Pay as you go costs $6 per hour/login.

The promotion is officially intended for users of a Kodak Wi-Fi digital camera, but is open to anyone.

Product page: T-mobile Hotspot promotion (via Fatwallet)