(no subject)

[ifmelfalls.livejournal.com]

I'm making a collage on one of my walls of my bedroom with postcards and pictures. I basically want to wallpaper this blank wall (my other three walls are painted)from corner to corner, ceiling to ceiling.
I've been using rubber cement to adhere the postcards to the wall, but over time some of them are starting to peel off in the corners or center making them bubble out.
My question is, what kind of adhesive should I use to get a nice flat stick and is also easy and quick to apply? It doesn't matter if it ruins the paint underneath (or even the picture's under surface) as long as it'll stick good.
Any recommendations or ideas?