Updated 12/12/11: I have cross stitched QR codes now for sale in my Etsy shop!
(See my original QR code patch!)
My first attempt at jazzing up a QR code. I've heard rumors that you can obscure ~30% of a QR code and it can still be read. For now, I've started with picking out patterns in the randomness of the code. For this one, I went through and found all standalone squares 1x1 or greater and changed their color. It looked fine on my pattern:
But not so great once I actually stitched it:
I think red was a poor choice of color (it looks like measles!) and the squares didn't translate so well with the X of the cross stitch on such a small scale.