I've never tried doing a head sculpt before, in fact I've barely ever used any sculpting packages before, so thought I'd give Sculptris a pop. Great piece of software, and also, it's free!
Basically a completely stripped down version of ZBrush, I would recommend this to anyone thinking of getting into digital sculpting as an introduction before taking on a more comprehensive package like ZBrush.
Very enjoyable to use, I'm sure I'll come back to this piece of software at some point and try something a bit more tricky next time.
The glasses were built in Max, and the first image was a quick Vray render also in Max.