Arroyo Seco canyoning trip?

There's a cool place about 2 1/2 hours' drive south of the Bay Area that offers a big watery canyon for swimming, diving, and various other activities.  In the summer heat, this might make a nice overnight camping trip or even a day trip.  I've been there once before with a group.  Would anyone be interested in coming along? 



More pictures here, including some that feature a naked Stanford Computer Science grad student (no, really):
http://theory.stanford.edu/~rvg/arroyo/