With regards to gadgets there’s only 2 things better than buying your own

1. Being given a gadget
2. Making your own gizmo

The book Gonzo Gizmos is all about the latter with projects like

• A rotary steam engine from a candle, a soda can, a length of copper tubing
• A hot dog roaster that only needs just a flexible plastic mirror, a wooden box, a sunny day, and algebra
• Levitating magnets

It kind of reminds me of the program Brainiacs. Available from Think Geek.