Not sure if I mentioned this program before, probably because it’s mucho denero however there’s a pretty slick program over at Singular Inversions called FaceGen Modeler. It’s an OpenGL based parametric face modelling software that generates high resolution texture maps, detail textures and exports to popular formats (no, not the Sims). The catch of course is that it’s $$$ (495 US) so I would consider that out of range for a tool for The Sims. It does have some cool features like random face generation (way better than Maxis’ head thingy) and age, gender, and race morphing. You could export it (if the demo allows) to JPEG or even a 3D format for later use. In any case, you can check it out here and make sure you click on the random face thingy on the page a few dozen times. It’s pretty cool too.