In the hills just south of San Jose are a cluster of sandstone boulders. When the winter days are cold, the friction on these rounded Font like blobs becomes amazing. For those looking to do some weekend bouldering near the bay area, Castle Rock is a great option. One of the most important skills required at Castle Rock is the mantle, or pressing out the top of a boulder. The rounded rocks don't have big jugs at the top, instead they have precarious mantles. Check out this instructional video on how to mantle.
A frequent member of the Berkeley Ironworks crew, Michele Lombardo Goodhew climbs at Castle Rock State Park-. Here's a video of her crushing The Lost Keys Traverse(V6). Check out the smooth moves she executes through the crux and through the hard mantle finish.A single hueco followed by a series of bad slopers below the Magoo Boulders was a long term John "Yabo" Yabolonski problem until a few years ago when Santa Cruz local, Chris Sharma dispatched the first ascent of "Ecoterrorist" (V10/11). Here's some footage of Scott Chandler hiking the problem. Watch the way he tops out the difficult problem.
Below Indian Rock are a number of less developed and very good boulders. There's good information about them on a Supertopo Thread. There's some awesome new mantle problems down the hill. Get out there and check them out.