My "portable vehicle" of choice is a unicycle (26" wheel in my case). It cuts the time in half compared to walking, and gets you mind off your troubles. Pretty much the same benefits as a scooter (good for ~1 mile trips, easy to stash) for about the same price (unicycles go much further on the high end, but a $150 one-wheeler is a nice ride). Requires a higher skill level and tolerance for odd looks, which is a benefit or drawback depending. I throw mine in the back of a small hatchback and park a half mile from work in a super-cheep lot, then get out and one-wheel it to the office. Started off riding it back and forth to school, because hauling my bike up and down from a third floor apartment sucked, not to mention concerns over bike theft. Nobody steals a unicycle...