I've developed a bit of a kit/instructables type thing for a color organ in an Altoids Tin.

Instructions PDF

I'm pretty amateur myself so the instructions aren't perfect and my circuit is a bit unrefined. Hopefully the abundant pictures make every step clear enough.

Target audience:
People who are relatively new to electronics but have built one or two things before. (I'm ordering lots of parts to run this as a quick build lab for freshmen/sophomores in Michigan State's Audio Enthusiasts and Engineers group.)

What you'll need to know:
-How to solder
-How to teach yourself a few software related things (If you've never used Eagle)
How to sanely lay out the circuit on a perfboard still have it fit in the tin.

What you'll need:
Soldering Station
Metal Punch (1/4" and 9/32" holes) recommended
Arduino UNO
Wire Strippers
Flush Cutters

I'd be tickled if any of you build this. I just wanted to show it off.