Tool Monger has a post about the book Forty Power Tools That You Can Make. Its from the 40's and has a varity of tools included. Its avialable online from several places.
Making Saddle cuts for a round tube project? I wish I had seen this Instructable in Grad School when it took hours making tight joints for a round tube project with a grinder. Check out this Instructable for a wuick alternative.
The Lift "N "Lock seems like a clever device for any shop to have on hand. Sure there are shims that you can use when you are trying to hang that last door by yourself, but getting that perfect height is still tricky. They run about $22 each.
Speaking of tools, this modified C Clamp is worth a look. The bottom branches out into a Y, providing a wider clamping surface. You can get one for about $12.
Now that distressing is in vogue outside of theatre, you can purchase tools to help you achieve the look. Woodcraft offers a kit for $25, but it could be made in the shop. Whatis interesting is the hardware that they chose to use to accomplish the look. Distressing is kind of like scenic goop or stage blood to me. Everyone has a different recipe, and the varients all accomplish something slightly different. It would be useful to have a directory of techniques, and an analysis of what is most effective for common situations....