After “tuning” in Photoshop CS5, I applied a plug-in called Pixel Bender.
It’s available free from Adobe Labs at: http://labs.adobe.com/technologies/pixelbenderplugin/
I believe it is only compatible with CS4 and CS5. The plug-in comes with 6 or so filters. The one I used is called “OilPaint”. Others can be found at a companion user site. It seems to have been developed mostly for creators of Adobe Flash media. But several of the filters work very well on still images.
It is a CPU and RAM hog and with my standard graphics card it took FOREVER to process. I installed an nVIDIA graphics card that my power supply could handle and now it runs smoother and faster (in fact, EVERYTHING runs faster and smoother). I still have to reduce the longest edge of my images to 1000 pixels and 8 bit depth.
This photo was taken at the Botanical Gardens in Bellevue, WA.