What's faster than Muni? Everything.
Maybe I shouldn't be too surprised at this -- but I'm kind of in awe that biking home from downtown San Francisco (entirely uphill, mind you) is faster than taking a bus.
GPS info riding my bike:

GPS info while riding the bus:

Here are the times: * Bike - 2.64 miles in ~18 minutes, 8.62 mph average. * Bus - 2.35 miles in ~20 minutes, 7.06 mph average.
(It might seem like I'm cherry picking, but I've recorded data from a number of different days. The bicycle is always faster!)
Times recorded using Runmeter for the iPhone.