A pretty cool idea
This is not a very big project, but its really cool. I discovered (well i bet a lot of others have done it before me) that it works really cool to make your own backround for a tank. I took butcher paper and cut it to the size of my small aquarium, then used magazine clippings from tropical fish hobbyist to make a collage. It looks pretty cool. I also had just the normal butcher paper as a backround on another tank, which looks very good to itself. It is just a solid white backround and the shadows of the ripples look really sweet. Plus it only took about 5 minutes.
My fish will kick your fishes butt