So I am curious as to whether or not a 12v 60w Peltier unit will work in a water cooling rig in lieu of a radiator. I've got one on the way and have several projects in mind but wanted to know if 1) the power would be sufficient to operate the peltier, and 2) using plexiglass will I run into any issues with case cracking?

Heres the link to the unit I bought: http://www.google.com/url?sa=t&rct=j&q= ... 5Cdavk-kSQ

No one? Guess I'll just have to wire everything and see if it works...

You still need a heatsink on the hot side. A peltier cooler works by transferring heat from one side to the other, pretty much a solid state AC or fridge. A regular fan and heatsink (or watercooling setup, for that matter) can only get as cool as the ambient air temperature. A peltier can make the cool side colder than ambient, but all that heat has to go to the hot side and be dispersed with a heatsink. Its also inefficient, so you'll need an even bigger heatsink to cool the hot side than you would need to cool the xbox normally. It will draw up to 60w, the actual cooling capacity will be much lower.
While they're neat little devices, I would not use one to cool an xbox/computer.

I kinda thought I might have to use a heat sink and I've got quite a few of them laying around. My main concern is whether or not the plexiglass will crack under the cooling.