I found this site a couple of months ago (and posted it in a thread!).
His cameras look nice and the workshop section is just detailed enough to allow you to make up your own plans. This is what I have done as my first 5x4 camera did not fold up. The next one will!
If you are serious about building your own camera, I can also recommend Dan Dozer's journal on his self build 8x20 camera. It is supplied on CD and runs to about 160 pages.
Most of it can be scaled down or modified to suit your prefered format. See the APUG classifieds for details.
(there was a url link here which no longer exists)
Steve.