Last weekend I biked up Mt. Tam with Ollie from work and it was amazing!! Heck of a ride - about 2.5 hrs up, a short break and Clif bar at the top, and then we zoomed back down in an hour!
Ollie had a super cool GPS-based bike mapping app on his iPhone, and we got some cool data back from it. Here is the map of our routes up and back overlayed on a Google Map. Note the trip up we didn't re-start it at one point so there is a break in the trail, but you can connect the lines I expect. :)
Bike up Mt. Tam
Bike down Mt. Tam