Altoids Amp: Curiously Strong Sound
These recycled Altoids tins are living a second life as pocket-sized amps. Use the speaker to pump up the volume, or plug in a pair of headphones to enjoy your own private rock concert. The ¼” input jack accepts electric guitar and bass, as well as MP3 players. The units run off a single 9V battery, and are advertised to use very little power and get 10X more gain than standard models. ($34.99 @ hesslerk)