I'm thinking of a couple things...

I'd like to paint my walls a lavender color. I thought about using one wall as an ever-changing mural and I was also thinking of having a house-warming party with my friends and we all paint on the wall.

I was also thinking, which would be very hard an expensive, is the cut into my wall to fit an aquarium inside as a center piece to my room. But that's way out of my knowledge on how to do.