A reference was made to one of these in a guide to network your pc to the xbox with two nic's. What exactly is this (pictures), and where can I find one, btw what does it do?

Try this website:
http://www.littlewhitedog.com/reviews_other_00009.asp
It tells you how to make one, but it basically gives you an idea of what it is. If you are going from your xbox directly to your PC, then you need a crossover cable. Basically the wires crossover to the other side in a crossover cable. If you are connecting to a router, you don't need a crossover cable because the router does the crossover for you. If I went into why they crossover, I'd get everyone confused because I don't really understand it myself

I'm pretty sure this is at least somewhat correct? Correct me if i'm wrong...

I have a router so I just take a !Ethenet! cable.. and smack it at the end of my box...?

yeah, I have a d-link router and I just used a normal ethernet cable and everything worked fine. it's only if your going directly to your PC that you need a crossover cable.

ok cool thats the same router I have.