Trolltech’s Qtopia is the application platform/user interface of choice of Linux handheld device manufacturers. It doesn’t matter if it’s a phone, PDA, or single application device. Hacker NK has successfully ported the GUI to the GP2X. With USB host mode,he’s been able to surf the web with Opera while using a full keyboard, mouse and WiFi adapter. The Sharp Zaurus PDA uses Qtopia with an ARM processor too and users have reported success pulling applications from the Zaurus software repository and running them on the GP2X. Here are some photos of the action one and two.
UPDATE: Commenters say that the GP2X forums have a Windows trojan. I think you’ll be fine if turn off Java.