If you are looking for something to do this Sunday, check out this post by Lumme on ODC message board:
Several of us have obligations in town this weekend, so we have opted for a local but nevertheless challenging alternative: 10,000 step staircase run on the Santa Monica Staircase (4th Street & Adelaide Drive, Santa Monica, CA 90402). We may run more or less, depending on how fast it goes, and maybe hop some stairs on one foot only . We will meet on Sunday at 1.50 pm on top of the stairs, and grab something to eat after the workout (bring a sweater or a change of clothes). Street parking.