Here I am last night putting the finishing touches on Got Wool? It took three evenings to bind, and last night I took three pieces of foam board, taped them together and mounted the rug on them by sewing through the rug and the foam board. I carefully sewed the rug onto the board around the perimeter of the rug by threading in and out following the troughs between the loops. This way, the threads aren't exposed and don't crinkle the loops. This is a great way to create a stiff and light-weight foundation for rugs that you might want to hang. The process only requires inexpensive foam board, needle and thread, and a few chairs to prop things up.
PS: no need to buy an expensive foam board cut to size by a framing department; I just used the cheap 20 by 30 inch foam boards that Michael's sells for a few dollars apiece, cut them to size with scissors and taped them together with clear packing tape.