My iman gets internet from a wireless router that has no ethernet outs on it. Can I run an ethernet cable from my mac to the my xbxox 360 and get it on Xbox Live? if so, how? thanks!
I believe that you would have to go into System Preferences > Sharing
Then you would turn on Internet Sharing and share your connection from AirPort to "computers using Ethernet.
From that point on I believe that the ethernet port on your iMac would act as an access point. There might be a few firewall issues, but that's the basics I believe.