I came across this tutorial the other day and gave it a try this morning; it sounded easy enough.
1) Open your photo and duplicate that background layer three times.
2) Turn off the top two layers and work on the first layer. On that first layer apply the cutout filter; Filter-> Artistic-> Cutout-> set the number of levels to around 4, edge simplicity to around 4, and edge fidelity to around 2. Change the blending mode of this layer to luminosity.
3) Turn on the next layer up. Working on this second layer apply the dry brush filter; Filter-> Artistic-> Dry Brush-> set the brush size to around 10, the brush detail to around 10, and the texture option to around 3. Chang the blending mode of this layer to screen.
4) Turn of the last layer. Working on this third layer apply the median filter; Noise-> Median-> set the radius value to around 12 pixels. Change the blending mode of this layer to soft light.
5) Flatten your image, give it a name, and save it!
Here’s a few examples of my experiments with this so far…
I think a brighter more colorful image will produce better results; I’ll have to revisit this again soon.