Depending on the size, I will sew them together until I have a piece that's big enough for a quilt. That's what I use for my quilts I give to homeless shelters. Most of the time those quilts will either get lost or trashed, so it's not like I'm out alot of money. I use Warm and Natural batting and the stuff is pricey at times. I usually buy by the bolt when Joanns has it on sale for 1/2 price and I get free shipping.
Smaller pieces are used as cat toys or for pot holders. I have even put some under the legs of my furniture. Makes it move around easier on this ceramic tile floor. :)