Seeing as a lot of people used Crazy Bump (myself included) but it went commercial some time ago, I tripped across this awesome open source software SSbump Generator. It can create normal maps, ambient occ maps as well as what appears to be a cross between them? Sounds like it was meant originally to create the normals for Source Engine but it most definitely can work with blender and the results are very very good. Check it out!
*PS* It also supports CUDA for any with a newer Nvidia card
- SSbump Generator 5.1 (Windows only)