The not-so-cleverly-named turntabletar is something that should never be used IRL. Still, there's no denying its novelty. Two midi turntable controllers have been melded with a mixer and strapped to something resembling a guitar neck. But instead of fret bars and strings, the neck has a crossfader, which, of course, is a DJ's best friend. Theoretically, any DJ-esque MIDI app (Ableton, Virtual DJ, Traktor) can be used with this thing (DJs, I'd like to see that remain a theory).
Ladies and gentleman, this is your keytar for a new generation.