Short clip of someone playing Slipstream on a Chapman stick. A chapman stick is basically like a guitar, minus the "body", with a much larger fretboard, which is made to contain more than one set of strings. This one looks like a standard 10-string chapman stick: it has regular guitar strings and bass strings. It's played primarily by "tapping" on the frets, so both hands can be used to make chords, melody, and basslines.

I've wanted one forever but they're very expensive ($1000+...) and probably fairly difficult to play. They're also kinda... nerdy.