Moved to Hardware Support
There are several threads in this forum discussing how to connect the 720 to the Internet using various 802.11b cards. Try a forum search and you'll find plenty of info about how to do it. Also, check the Hardware Compatibility List to see which cards work:
http://www.hpcfactor.com/hcl/
I've gotten good results with the Agere ORiNOCO Classic card.