I would walk. Seriously. Not only would you get their quicker...think of the awesome exercise.
You're right, it would take less time walking. I often think about taking my bike, but that is dangerous and I'd be competing with the motorcyclists zig-zagging between the cars. Only problem about walking is that 9 months of the year is the rainy season and it's usually over 80˚ and very humid - your strongest deodorant wouldn't last the first half mile! I'd have to take two changed of clothes; i.e., a raincoat if it rains, and dry, clean clothes to change into when I get there, plus my computer and it's accessories. Granted it'd be a good workout, but impractical for me.