Ask and ye shall receive. That's apparently the case where practically anything related to Guitar Hero is concerned.
Last summer we posted what we thought was a silly Photoshop concept of a DS Lite with the neck of a guitar controller grafted onto it, but apparently it wasn't so crazy after all. Engadget says something called the "Guitar Grip" has actually been developed for Nintendo's DS, a truncated version of the Guitar Hero neck with four fret buttons instead of the full five.
It still seems like it would be a bit awkward to strum the touch screen that way, but we're certainly no experts. If we were, we'd be bidding on that Rock Band mod kit instead anyway.