One of the big news stories this week was about Zipcar’s (ZIP) initial public offering. The company, founded 10 years ago, has headquarters right near my house and I pass it frequently. If you don’t know, Zipcar is a car-sharing service that’s popular in cities (like mine, Boston) and among college students–basically with people who are unlikely to own cars. Members can rent cars, located in convenient spots, at an hourly or daily rate and they pay an annual membership fee. This allows a lot of flexibility because the cars are parked all around cities/college campuses and eliminate the...