Some older creations, but two of my favourites.
A couple of years ago, I became fascinated with the possibilities inherent in home-made musical instruments. I stumbled across a website dedicated to cigar box guitars, and set about making one of my own. I found a beautiful box in a second hand junk shop, and used the neck from an old kids acoustic. The result was the Lankwood Fonseca (named for the brand of cigars). It has a very high action, and the bridge is closer than it was on the original guitar, so I took the frets out and made it a slide guitar. Then I set about teaching myself how to play it. I'm still at it, and can play the odd passable tune, or at least something resembling blues.
A year of so later, I picked up a pool cue case from Chapel Street Bazar for 8 bucks. When thinking what I could do with it, I struck on the idea of creating an electric lap steel guitar that was its own case, and built the Lankwood Hustler. I put the process of building it on Instructables.
The Hustler has only three strings, and sounds pretty terrible. It's more of a display peice than an actual instrument.
I then attempted a cigar box dobro, using a strange metal dish with two semi-circle depressions. This one is still sitting on my shelf, half finished.