I had fun playing with GIMP today. Here is the base image::
Camera: Canon EOS Digital Rebel XTi
Aperture: 6.64 EV (f/10)
Exposure Program: Normal (green square I think)
Focal Length: 70.0mm
Post Processing: Levels (manual), Brightness (-5), Contrast (+10), Unsharp Mask.
And here is after cropping (with saturation turned down some):
And here's where it got out of control and I started using some auto option filters in GIMP. I call this one "Cat" since it's similar to one of the filters that Cat at the Whimsical Gardener uses. Of course, hers turn out much better, and have more noise in them (thus making them look even cooler, naturally).
And here's a Mandelbrot filter (named after Benoit Mandelbrot, the father of fractal geometry). I call this one "Philip" since it looks like something that Philip at East Side Patch would play with (but of course, again, he would do a much better job than I would).