Five4Footprint Numero 4: Bicycling....
There are few great joys in life then self locomotion, and none is more efficient than riding a bicycle. Supposedly almost all the energy applied to the pedals is transferred to the wheels, according to Wikipedia A human being traveling on a bicycle at low to medium speeds of around 10-15 mph (16-24 km/h), using only the energy required to walk, is the most energy-efficient means of transport generally available. Given how efficient it is there is no excuse not to try to ride to work on a bicycle.
If you need a safe route, most of the Santa Clara county cities have bike maps you can pick up or order. For instance this is Mountain View's Bicycling Map available online. Use your favorite search engine.
There are some downsides, you do get sweaty. But if your workplace has a shower then you are set. Be sure to choose a bag that rides on your butt or lower back instead of your back. This reduces the sweatiness of the ride. It's no accident that the Timbuk2 and Crumpler messenger bags are the way that they are. Depending on your rig, it's probably nice to store your bike in your cube if you can.
Then there's the safety factor. The New York Times Freakonomics Blog had a post on "Will Bicycling to Work Get You Killed?" A very scary headline with some interesting facts.
Did you know that riding to work on a bike is more dangerous than driving, however if you survive the ride, you're likely to live longer. Presumably due to better health, greater happiness (did I mention riding is pure joy) or just better Karma (no not carma).
The most interesting fact from the blog is that risks of riding a bike drop considerably the more bikers there are on the road. So make bike riding safe and get on the road.