Here is a few projects I like and wan't to do when i get the time.
The first one is to make a HHO electrolyzer. I have embeded a metacafe video for you to enjoy.

Build A 32 Plate 31 Cell Series HHO Electrolyzer Make Hydrogen F - For more amazing video clips, click here

I would like to get the perfomance of this one. Just imagine the torch/cutter you can build with this one. Sorry it seems i can only get a link for it. #blimer# HHO Hydrogen Cell 1.2

The second one is a diy plasma cutter. It will be a while before I make this one because of money.

How To Build A Homemade DIY Plasma Cutter - More free videos are here

The third one is a sterling engine.Go here for more info about sterling engines. Here is a metacafe video of a diy one for your enjoyment.

Megan's Stirling Engine - Watch more funny videos here

I'm in the progres of bulding a cheap and powerfull diy laser(LINK). I was in the middle of completing it and my laser blows up. Now I have to search for a new one.

There is many more things I want to make but I'm not going to list them right now.