a few days ago i saw this lifehacker article:

http://lifehacker.com/software/how-to/build-a-wi+fi-adapter-for-your-xbox-360-on-the-cheap-306678.php

the main reason i dont have the xbox wireless adapter is that i refuse to pay 100 bones for it. however, $30 is totally reasonable. plus i always wanted to make a bridge out of a router. it ended up being a little tricky because of the buffalo routers i used, but the end result is that my xbox is now rocking the internets.