I just discovered headboard decals, and I think they're amazing. Wall decals in general are great, especially for renters. You can change the look of a room without painting. It takes less time, is so much cheaper and no paint fumes in a small enclosed space. :)
I found the two above at Urban Outfitters. They're both on sale right now, and I they're both under $40. Find them and other great decals from UO here.