Alright, here ya go guys.. As for now this is just to satisfy the few of you that keep asking me about this mod.
To get the network activity led on the outside of your xbox just do this.
NOTE; There are 2 differnt kinds of network setups in the xbox, one is in the following picture with the lights exposed, the other is an enclosed one. As for that one I need to play around and get a tut out for that. So here's the one for the exposed lights.
All you need to do is set up your basic 5v power source and resistor(or whatever, just make sure you use the proper resistor).
Now run the power line to the right side of your led, and the ground of your led is going to solder onto the left one of the legs of the orangeish/yellowish light (the left one that you look at from the inside of your xbox), as viewed in this picture.

I took this pic from a customers xbox... just to make this fast.
And that's it. When you do anything through your network, this will flash like crazy!
Now this should satisfy you for now, I will find the points for the ground in the enclosed network one. If you're wondering what this is, you see how you can see the lights and exposed wires in this pic.. well the other one is total enclosed with a metal "case" around it. So i know there has to be a bottom point or something around it, just gotta put some time into it and follow the traces for ya.