A few months ago while in nomail status, I read in the archives a post
by a listee who had made a toilet seat to fit on a 5 gallon bucket.
  This seemed like a good idea, but I didn't get time to try it before
this summer's camping trips.
Recently at a Bass Pro Shop Outdoor World, I found that they already
sell them for $9.99.
  Available at their online store:  basspro.com
search for: "Little Jon"

We found that it works well.  We line the bucket first with a kitchen
garbage bag which is about 2 ft by 2 ft-6 in.

Larry A.