Yeah I'm in the same boat. College student. I've lived in dorms and put up posters and pictures all over, but next year I'm moving to a more permanent apartment situation and so I've been searching her on Craftster for ideas. Try starching fabric to the walls or using contact paper. I'm going the contact paper route and making big 5-6 in vertical stripes on two of the walls of my bedroom and then I'm hanging some artwork. OH and check out the rasterbator(http://homokaasu.org/rasterbator/wizard.gas?Phase=1
). I'm a little obsessed with rasterizing right now. Just blow up an image you really like and use it like mural or wallpaper. Or make tall fabric covered or painted panels (plywood or even foamcore) that you can set on the floor and lean against the wall (you can take them with you when you move). They make good headboards to! Good luck, there's so much you can do. You just have to get started thinking in the right direction and then the ideas don't stop!