Can one of you explain how it is physically connected? I assume you hook up the xbox to a hub/router/ or daisy chain it to a box with two ethernet cards?
Also, it tells me on the web page that I have to pay? What gives with that?
xbconnect is free. You have to pay for the pro version but it doesnt really do anything worth the price so stick with the free version. http://www.xbconnect.com/downloads.php
As far as hooking it up, you can either install a second nic card in your computer and connect directly from the xbox to the pc with a crossover cable or, you can get a hub or switch and connect the xbox, computer and cable/dsl modem all to the switch/hub with straight through cables. I beleive dlink is selling a cheapo switch at best buy for around 30-40 bucks that will work perfect for this.
If the two xboxes are close enough together to directly connect, you can either conenct a crossover cable between the two, or connect both to a switch with straight throughs and you dont even need to use xbconnect, but the game must support system link gameplay.