In the past, I've reported that the Belkin Wireless USB adapter works out-of-the-box with Ubuntu. It seems not so for Feisty. The module for that particular chipset is broken. Not sure how, but I'm hoping it's fixed in Ubuntu Gutsy Gibbon 7.10 - due in October.
For anyone who surfed and purchased one based on my recommendations, sorry. If you want to save money, download a copy of 6.06 LTS Dapper Drake, or the previous release 6.10 Edgy Eft. The USB adapter works fine in those versions.