There are a couple of "do-it-yourself" sort of options that you can try.
One is to get yourself a regular wireless ethernet bridge device. This will take any standard wired ethernet port, and turn it into a wireless one. Though it probably won't be much cheaper than the official 360 wireless adapter.
The other option is to get a cheap router that has WDS (Wireless Distribution System) capabilities, and use it like a wireless ethernet bridge instead of a router. Cheaper, but you have to deal with the power adapter for the router, and it complicates your overall network config.
But so far as I know, only the official 360 wireless adapter will work if plugged into a USB port on the 360. So you can't just go get any old USB wireless network card and get it to work.
Is there a way to access xbox live with out buying the $80 wireless adapter or drilling holes in my floor/ceiling? My broadband access is hard wired really far away from my console. Please help.

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