I saw where you can apply fabric to the wall using startch. They stated that the fabric was an excellent way for renters to personalize their space.
I would make a desk with some ply wood (it could be painted outdoors). Metal shelf brackets and shelves (again can be painted out doors). Baskets for your craft supplies. You could either leave the closet door on and put cork board or a chalk board on it, or remove the door and hang a matching curtain...
Another good idea along the lines of Kimberly... Spray glue a peice of poster board, cover it with fabric, and cut to your deminsions and use poster putty to stick to the wall. We've used this in our daughters room a lot.
That won't damage the walls?
Thank you for the ideas, I will give them a try :)