Xbox 360 Wireless Adapter

I got a 360 about 2 weeks ago and i decided i wanted to play Live. My internet connection is about 3 rooms away and i dont want a 50 foot cable running along everywhere, so i thought hey why dont i just buy a wireless adapter?? So i checked online and its close to 100 dollars. Does anybody know of a cheaper way to connect to the internet than having a huge cable or a really expensive adapter??

:huh: