Here are some I made:
http://www.quiltingboard.com/picture...s-t153884.html
http://www.quiltingboard.com/picture...t-t209062.html
I got most of mine from the Salvation Army. The SAs in this area are great for culling out shirts with problems (stains, rips etc.) so mine were all in pretty good shape. If long sleeved, look at the elbows for wear. If the fabric looks thin, don't use this portion. Also, look at the underarm area. If it looks discolored at all, cut it out. It's my understanding that deodorant can weaken the fibers. I think I've made 3 more quilts that I didn't post. Cutting everything into charm squares really simplified things for me. The shirts were different weights, and all played nicely together. They were all 100% cotton, or a linen cotton blend. no Poly. I know some have been washed a couple of times and are still in good shape.