There is such a thing as peel-off wallpaper glue! Technically, it's called strippable wallpaper glue, and a lot of the time it comes already on the wallpaper. The only catch is that when you peel the paper off the wall, the glue is still there and you have to sand it off. What I would really suggest is to go to your local paint/wallpaper store and inquire there. Either they'll have it and all the directions that go w/it, they'll be able to get it for you, or they'll tell you it's only available already on the paper. But in any case it's worth a try!