This is my own variation on the common curcuit tutorials that have been floating around on various PS sites.
The pictures are pretty self explainitory. Make sure your foreground and background color is set to black and white (Hint: Press D then X).
Filter>Render>Clouds

Filter>Brush Strokes>Accented Edges

Filter>Pixelate>Mosiac

Filter>Brush Strokes>Accented Edges

Add some color to brighten it up a bit, here's what I got
