As I've mentioned on this blog before, I'm an Engineering student, and this kinda shit blows me away.
Basically, robots that can recognize the color of the fret in Guitar Hero, and "plays" the note by flipping a switch and pressing the button.
You have, of course, the original, SlashBot:
Now, while both are amazing, I think the BIGGEST flaw is, as the later video shows, fast strums, or really alt-strumming in general. From observation, they seem to have the little piston that flips the strum bar to the perfect distance where the bar goes far enough to recognize the strum, but not so far that it comes back so that it can flip it as fast in only one direction as flipping it up and down.
One thing that I can reccomend to off set the "fast note" problem seen in the CythBot is to also allow for width detection. If the camera detects something the width of a note followed by something of the same color, but narrower, then hold the same fret(s), but if it's followed by something of the same width, then it strums really fast.
But which one is better, you ask?
All right, FACE OFF: CLIFFS OF DOVER!
96%, good job SlashBot!
99%? Cythbot Wins!