There's also a very nice software called David that allows you to do good quality 3D scans using a camera, a laser pointer and some patterns printed on paper to calibrate the whole thing. Someone where I used to work until recently (my choice, moving to Tokyo soon :) ) used it recently to produce some really good quality scans of the faces of a number of people who work there. He quite mastered the whole process and the result was very good. Good enough to impress our character modellers (who still do better work, but a face scan can be done and exported in half a day, which is definitely not bad...).