I made one by drilling a hole in a body cap on an old SLR and taping the pinhole to the inside, but there are as many different ways to make them as there are people using them it would seem. Take a look at www.f295.com - they have a forum for camera building there that may provide some help if you don't find what you want here.
13 Critchley Avenue, PO Box 36, Monteith Ont, P0K1P0
There's a ton of ways to make a pinhole camera. You can use a cardboard box, a tin can, an oatmeal box, etc.... All that's needed is a way to hold film or paper, a light-tight housing and a pinhole in a thin sheet of ??? to let light through.
Here's the one I built : (available daytime Eastern only)