Like many of us, I have bought a couple of jelly rolls, and had no idea of what to do with them. After much humming and haaing, I've finally started on a pattern that I like.
This pattern appears in the current McCalls Quilting special America Makes Fast Quilts which has lots of designs for charm packs, jelly rolls, fat quarters and fat eighths. There are quite a few nice designs in there, but I particularly liked this one. The quilt is supposed to be 72"x88" and uses 4 jelly rolls, but I'm sure that I can get something reasonable out of a single roll.
I still haven't decided on what to do with the guitar fabric yet, but this should keep me out of trouble while I make up my mind.