I'm building a workbench this weekend that I built once before in a different house. It's basically a 4'x8'x15/32 plywood sheet (smooth on 1 side - $23 at Lowes) cut in two lenghtwise (two pieces 2'6" x 8' and 1'6" x 8'). I frame out the 2'6" x 8' piece with some 1x4 (these need to be straight but you don't need shelf quality). 5 2x4 (40" long) make up the legs (3 on the back side, 2 on the front). On the back of the bench, I mount a piece of pegboard and the leftover 1'6" x 8' piece of plywood is mounted underneath as a shelf. On top of the bench I use a piece of sheetrock cut to fit the workbench which makes a great very flat and pinnable work surface. And as has been mentioned above, when you get glue and dings and too pin holes and cuts on it, you just get a new sheet (for around $6). Add a light duty vice ($30), a working lamp ($10) and maybe an overhead flourescent shop light ($25 or so) and you have a really nice setup for less than $150. If I finish it this weekend, I'll post some pictures