I think I've finally found a good, unique, and functional soap mold!
I made some Raspberry Aloe Soap in my new mold. As you can see from the picture, the mold consists of 3 equal sized pieces of wood and two end pieces. I drilled holes in two of the boards and inserted two threaded rods and attached washers and wing nuts on each end. I wrapped all the pieces of wood in plastic.
The mold as pictured, holds two pounds of soap, however you can adjust the end pieces for smaller batches if you'd like.