I made this small kitchen rug out of 13 old t-shirts. I was inspired by this post: http://www.craftster.org/forum/index.php?topic=246454.0
For mine I decided to braid and then weave the braids to make a small rectangle (sort of). Then I wanted give the edge a more finished look, so I trimmed it with grosgrain ribbon. I had trouble sewing through the braided t-shirts on my sewing machine, so I used "stitch witchery", that iron on stuff to fuse the t-shirts to the ribbon, then I hand sewed it all the way around. The only thing I was actually able to use the machine for was finishing the edge of the ribbon so it didn't fray. It took me a while, but I was really casual about finishing it. I switched techniques half way through the braiding process. At first I was making my husband hold the ends while I braided (which annoyed him), then I learned I could sit on the couch and step on the ends with my heel while I braided (which kinda gave me a cramp in the back if I did it for a long time without a break.
In retrospect, I could have made the weave tighter and I could have tried to make the rectangle less lopsided, but that's difficult when using all different textures of t-shirt. Maybe next time I'll make sure I have all the same kind.