I'm currently writing a parallax mapping shader, and it would be nice to have some decent media to play with to see how good the shader looks. How about a high-poly scifi-style crate which has a lot of detail but is essentially still based around the shape of a cube? Then I could make a normal map and height map from the high poly version, and put them onto a cube with parallax mapping. No need for you to do the normal map or height map, I can make those from the geometry.