I drove a Honda Spree during the First Gulf War, and for a few years after. It was 7 miles to work. I loved it. However, my sense of balance became so bad and I turned it over a few times (scraped knees were the worst injury but I didn’t want to push my luck) and finally sold it. If I get another scooter it will have 3 or 4 wheels on it. Maybe a Zap.
You really have to watch the condition of the road in front of you-especially broken glass and other clutter, and storm drains that you can drop your wheels into. The second big concern is for decent review mirrors to keep a close eye on traffic getting too close to your rear.
Try the Honda Gyro: http://www.youtube.com/watch?v=YJ5nUdpisys and http://www.youtube.com/watch?v=_70-jBCyNVQ
You pretty much can’t tip it over in normal use.