Bicycle Mechanics - Cracked Rim Usable?

I was being a complete idiot and manged to crack my Trek Matrix rim when I was adjusting my brakes, I was trying to bend the calipers to align them right and had the pads off, instead of bending they just pulled towards the rim and it cracked on both sides of an eyelet where the calipers hit it. I know I [I]should[I] replace it but I got them on CL and there's no way I could afford anything half as nice to replace. What exactly happens if the spoke pulls out, how much will it throw my rim off? Could I take that spoke off and tension the other two a bit more to make up for it? Basically, is there any way I can still use this wheel even if it won't work as well? If not, what about rebuilding it? I've never built a wheel before a on't hve a trueing stand but... is it the sort of thing I could figure out with a lot of time and reading, or can I not get around needing the truing stand?
Thanks

well, its usable, but the question is, how safe is it, and how much do you feel like gambling with your personal safety?

take a pic of the crack(s) and post them for us to see, then we can judge better ;)

I'll put a pic up when I get a chance, no camera at the moment. What makes it dangerous, what happens if the spoke comes out? Wouldn't it just throw it out of true, or is it more dangerous than that?

If a rim is visibly cracked, it should be replaced. It's not good news, but there isn't a fix or work-around that is more than a stopgap measure for this situation.

I'll put a pic up when I get a chance, no camera at the moment. What makes it dangerous, what happens if the spoke comes out? Wouldn't it just throw it out of true, or is it more dangerous than that?

Typically, when a spoke pulls an eyelet or the rim cracks around the eyelet, the wheel will just go quickly out of true. Unfortunately, from the point it goes out of true to a complete taco is totally unpredictable. If that point is reached when you happen to be bombing down a hill, then you are f*cked.

The only really safe and sensible thing to do is retire that wheel. That's just my opinion, but I think you'll find that anyone in a bike shop will tell you the same thing. Operating on known defective equipment of any type is just asking for trouble.

Do some searches for catastrophic wheel failures, look at the pretty pictures and ask how much your teeth are worth :)

Good news is you could probably reuse the hub.

Another vote here for ditching the wheel. Not worth the risk.

Alright, I'll take the consensus and ditch it. However, think I can ride it 2.5 miles and back to get to school tomorrow, if I'm careful? i don't have much of a choice but if you all say it's suicide I might rethink... Thanks

If it's the back I'd risk it more than the front, but don't blame anyone if it dumps you while taking out your deraileur and frame.

I'd use it. As a hula-hoop. Dig deep and pay the Stupid Tax.

Could you please provide a URL for parktool or Sheldon where they employ that method of brake adjustment? :)

I don't get how you messed your wheel adjusting the brakes. You were using the wheel as leverage?

Unfortunately for you, I have to agree with everyone else. About the only thing you can do for any crack in any aluminum part is find a recycling bin. Sorry. Ditch it...your life may depend on it.