In the US (unsure about t-mobile outside US) you can get a t-mobile micro sim card, sometimes free or $0.99 but currently $10, and activate it for 200MB/month free data. Wonderful starter program and great for developers too.
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?