In honor of Jackson Pollock's birthday, please allow me to post this link to a wonderful flash site where you can make your own drip painting.
I found it about a year ago around this time... probably on his birthday.
Click the mouse to change paint colors. Press the space bar to clear the painting, press esc for more info on the creator. Post your creations! (I just used "print screen" -- let me know if there's an easy way to export these...)