I bought a used iBook 500mhz and got it in today, it did not have the airport card installed and i have a new Belkin F5D7050 USB wireless card from my PC that is just sold, i read online that there is away to use the Airport Setup Utility to install the USB wireless card. here is my system info if that helps

iBook g3 500mhz (Dual USB)
198mb Ram
OS X 10.3.7
Airport Setup Assistant v.4.1 (with support for airport express)