Just want to report that after awhile of playing around with my network settings, I found that it is easy to get Xbox Live to work on the 360 through a wireless PC bridge. Please Note, I am having an issue still with this connection. Heres what I did though:
1. Connected xbox 360 to laptop with cross over (though cross over cable is not req.)
2. Connected to wireless network in my house
3. Bridged the wireless connection to the nic that is connected to the xbox360. (make sure that both network connection icons say "connected, bridged", and that the bridge icon says connected. If they dont say "connected, bridged" right click on each one and click "add to bridge")
Ok now the new stuff
4. ALL SETTINGS ON my COMPUTER are set TO AUTO (IP, DNS) DONT PLAY WITH THE SETTINGS ON YOUR PC.
5. I viewed the status of my hub (to do this type this in your internet browser http://hubs ip address here/) and wrote down my LAN settings not WAN!!). You need to know the hubs current ip, dns, and subnet. On a linksys hub, to view these settings just click the status tab.
6. I then went to the xbox 360, found the network setup screen, and change the IP to manual. For the ip, i entered my hubs ip, except for the last number, that must be diffrent. For example: my hubs ip is 192.168.1.1, on my xbox360 I set the ip to 192.168.1.6.
7. My subnet mask is 255.255.255.0 so i set it as that on my 360
8. I set my gateway to the same EXACT IP as my hub. So in my example, 192.168.1.1
9. Next i went to dns on the 360, and set it to manual, and entered the dns1 and 2 exactly as they read from my hub.
10. jackpot it works
One small catch, I lose connection to xbox live after 10-15 mins or so. I can reconnect to Xbox live fine, it just always loses connection in game play. Anyone have any idea why? Or a potential Fix I can try? If other try this, let me know if you get the same problem. This may just be my network.