If you want to try it out, you can download it from Adobe Labs here: http://bit.ly/bmQkQC and Russell Brown has an excellent tutorial on it here: http://bit.ly/d8CcpK
This is just one of the effects available in Pixel Bender and it's called Oil Painting. Yet to experiment with the others. I'd be interested to hear what you think...
Here's a couple of landscapes with 2 different treatments.
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