This one I just let run over night.  I'm restarting it since I accidently picked the wrong normal map for the boots.  It does, however, demonstrate the power of normal maps.

What I do to create a normal map is, I take either the diffuse texture or the bump map into GIMP.  If it is the diffuse, I then run the Normal Map plugin (not included, but available online from here).  I usually choose Prewitt 3x3, as it doesn't make it over powering.  Prewitt 5x5 makes it pop more, but it can look pretty fugly, too.  The normal map tutorials I've seen also mention using the green channel when using the original texture.

If it's the bump map, I first invert the colors (colors->invert), then I run the normal map plugin with the same settings as before.