Here at the Engadget HQ we're very serious about articulating the noise and action of a bow when it comes to our synthesized string instruments, and the O-Bow looks like it could be the low cost solution we were dreaming of. (No, Smule Magic Fiddle doesn't count, it's a devil "instrument" and it lies). Hacker / musician Dylan Menzies has devised a method using the optical sensor from a mouse for tracking anything with a grained surface, like a wooden stick, and using it to make a single sample synthesizer "sing" like a real bowed instrument. Unfortunately, that single sample sounds pretty terrible right now, but Dylan is working on a more sophisticated method of modeling the instrument.