Thorn (a.k.a. pinkdino) posted this very nifty thing: it's a figure/gesture exercise tool for artists. (WARNING: Contains nudes.) Basically you set how long you want each picture to show, and it goes through a slideshow of models in various poses for you to quickly (or not-so-quickly) sketch before the next slide pops up. Very simple implementation, but a great little exercise.
NSFW -- There's not way to select "no nude models," but you shouldn't be doing sketching exercises at work anyway, right? *hides sketchbook under desk*