I've been searching for something to hang on the wall behind the bed.
Finally Groupon solved my problem. They had a coupon for Dali Decals. The pieces stick on the wall and then can be removed when you are ready for them to come down.
We settled on this 3 piece set and I love it. It was pretty easy to stick to the wall and it fills up the space really well and the biggest plus - Michael can sleep easy knowing nothing is going to fall on his head (just once I hung a picture and it fell off the wall at night and now we can't hang anything over the bed).