If your like me and to cheap to fork out for the price-tag-hefty wireless adapter for the xbox 360. Sharing your internet through your mac via the ethernet port is the easiest and cheapest way to go.
1)Start Internet Sharing
2)In Terminal, type cp /etc/bootpd.plist /tmp/bootpd.plist
3)Stop Internet Sharing.
4)Open /tmp/bootpd.plist for editing using TextEdit or whatever.
5)Locate this section of the file, near the end:
6)Change the value 4 to 0.
7)In Terminal, type sudo cp /tmp/bootpd.plist /etc
8)Start Internet Sharing.
9)Check that your change to /etc/bootpd.plist hasn’t been reverted.
I hope this guide has helped you. I just want to say that i did this guide on a macbook pro, but I know that it works on a macbook to. I don’t know about iMac’s and Mac Pro’s. I’m not liable to any damage that you may cause in doing this (which should be none).