uSketch is the best tool for creating sketches from your images.
With a very intuitive and simple interface, uSketch allows you to take a photo, select the sketch you like better and share it right away.
You can't do it easier!
works on all Macs running OS X 10.7 (Lion) and supporting at least Open GL 2.0
unlimited image size
full screen mode
12 sketch effects
13 image filters and 6 presets (good combinations of filters)
load image from disk / take picture with camera
share on Twitter, Facebook, Flickr, email, save, print