The advice above is technically correct, but not ideal.

Converting standard textures to bump maps can yield innapropriate results.

There's really no easy way to make a GOOD bump map, or displacement map for that matter (a much neglected area).

The options above can certainly work in many cases, don't get me wrong. They're just not a cover-all solution.

If we can hit that bullseye, the rest of the dominos will fall like a house of cards...checkmate!