Old La Honda rd (abbreviated OLH) is a standard "test climb" for local racers. Eric Heiden (USA speed skating olympic gold medalist, also a pro cyclist) held the unofficial record when he was studying at Stanford after he retired from racing. Below 20 minutes is good. Under 18 is very good. Eric's record was 15 something, and I have heard that it's now in the 14s.

It's a 3.4 mile climb with 1300 feet elevation gain.
http://graphics.stanford.edu/~lucasp/gr ... honda.html

OLH, Page Mill road, and my favorite of the three, Kings Mountain road, all ascend the ridge to the west of Palo Alto. From there you can return, or take the highway along the ridge top north or south, or go west to the ocean.

Klimb (http://www.klimb.org/klimb.html) is a great tool for mapping rides in the bay area.