I really like these really simple, lightweight Dobbsonian telescope designs. Most Dobbs are big and awkward, and use up a lot of plywood. But one of the newer trends is to make the box that the scope sits on as small as possible. This is fairly tricky, in that the bottom of the scope has to work as a counterweight for the top, so it's a fairly difficult design exercise.

This very lightweight scope has a spider (the part that holds the secondary mirror on the inside of the tube) that is made out of stressed wire -- interesting stuff!