|I discovered this when I went through a spate of alterations on several patterns. I have a homemade dress form made from the brown paper tape (thanks very much to my sister for her assistance!!). Unfortunately, pinning into my paper twin is darn near impossible, unless I was very determined and didn't mind ruining several pins. In a fit of desperation, I used a piece of medical paper tape to tape tape my pattern to the form. And lo, the medical paper tape has a low tack so that it is easily reposionable on the dress form as well as the pattern. Medical paper tape is made by 3M and is usually found in the pharmacy section of Wal-mart, Publix, etc.
On a related note, blue painter's tape might also work too--I've read here that it has a low tack as well. Probably cheaper.