I have been recently working on a flying robot plane called the "Towel". I got the plans for this from the Make volume 31 that I received recently. It consists of a triangular frame with one motor made out of foam board but I used cardboard. I decided to add a few bells and whistles so I added fold-able wings so that you can have either a V-tail or a regular wing. I assembled it in about an hour using a few zip-ties cardboard a box knife and a scroll saw.
You can find all the instructions and parts lists here:
Update: Like many of my other projects, this never got off the ground literally and figuratively.