Here's one I actually built. In 1982, I worked for Douglas Aircraft Company for a few months (college co-op program) and lived just a block or so from the beach. A lot of guys flew slope soarers above the beach, so I threw this thing together to join the fun. Well, "threw" is a good word, because on the first flight I threw it over the cliff, but forgot to turn on the switch (dumb!). Luckily, it was built straight and it arced gently down into the sandy beach, no harm done. It provided a lot of relaxing stick time.