I just built the linux-wlan-ng 0.2.2 drivers, and seeing as they're not that easy to build, I thought I'd share them with you.
http://archive.gp2x.de/cgi-bin/cfiles.cgi?0,0,0,0,19,1791
This module will add support for Prism2 USB based WiFi sticks to your GP2X. Just follow the instructions in...