Pilot Knob is a small hill but has a great view and is well worth the short climb. There are many access points to the area but the closest parking is the Lake Lagunitas Parking Lot. Head up Lakeview Road to Pilot Knob Trail. Just note there is an $8 parking fee if driving in on Sky Oaks Road.
I was surprised there was no cache up here already, but I found that there have been two in the past. Neither survived long. I've hidden this one well, hoping that it will last longer. It's a green matchstick container two feet high in a Tanoak tree (thanks to J5 Crew for the identification!) about 50 feet NW of the tree at the top of the trail. Please just remove the cap and leave the container in place when signing in, and try to keep well hidden.
Mt. Tam from Pilot Knob
Picture above shamelessly stolen from tiptop3's log. The one I took was not nearly so nice.