i have heard of obidian  knives and was wondering if any one can describe how they are knaped?

Basically, you have to hit the larger rock with a smaller one at just the right angle and area to detach a large flake, preferably about 6-7 inches in length. You're going to lose some material just to breakage and sharpening, so best to try to make it thicker and longer and wider than you need, as you can almost always remove rock, but never add it. Pck one side to be the blade, pick a handle and start chipping off small flakes from the blade area by light tappings at about a 130 degree angle from both sides, alternating to produce a sort of wavey edge, which actually works out to be straight, or mostly straight when finished. Use an abrasive rock to abrade the top and tip of the blade area and make handle area smooth enough to hold, wrap it in leather or suede or make a wooden handle, and you got yourself an obsidian/flint knife. Granted it will be small, but because of the fragility of the material, this is for the best.

Crap! I go back to university here in Virginia then. Oh man, that sucks...

Know whats good for knapping flint? Those old can openers called church keys. They work wonders. 

some cut fingers