Digital peice of Megan Fox, I did about three, building up thee exaggeration a little bit each time, this was good practice. I recommend doing that for anyone that wants to do caricatures.

Exaggeration PLUS likeness, is the hardest damn thing to do. Portraits are easier than a good caricature.

EDIT- I don't really like the likeness on this one, but scince shes famous I thought Id post it, heres more digital stuff for friends, i posted references too under them.
http://kamikazepanda.blog spot.com/2010/02/friend-s ketches.html