excellent contribution, will try it sometime!
Parallax is the way to go! Experiment with the map to get different results, you will be surprised how deep it can go.
I've gotten what looks like 5-6 inches deep on a brick wall!
Be careful, you can easily streak the edges of the bumps by going too deep, the pixels stretch. Its amazing to actually see a brick 'block' another brick when you get close to a wall...Imagine a detail in the grout that you cant see when you get close to the wall...Its going to be amazing when parallax mapping makes it into retail games, we are ahead at this point...