Here's a neat set of 30 abstract brushes for Photoshop CS3.
Took a flashlight and some other cool stuff that could emit light, set my camera for a 4 second shutter speed and went nuts. Will probably work with CS and CS2 as well as CS3. Older versions I have no clue. Use freely with no particular permission, but it would be nice if you could link back here from some sort of description of your work, just so that others can take part of the brushes as well.
BUT! Keep in mind - Creative Commons Attribution-NONCOMMERCIAL-Share Alike.
Nothing commercial without me getting profits or sandwiches...
Don't take credits from others work, and don't drink and drive.