While another car-sharing service got into Philly first and grabbed much of the market, of late an outfit called Zipcar has been making what can only be termed 'inroads' in to the car-sharing customer base. At the Go Green Expo in March we talked to Quinn Callahan about why this is, what advantages Zipcar offers, and generally what distinguishes the two companies.

We challenged Callahan to go for this whole 3-minute clip without naming his rival company, but he was either unable or unwilling to do so. At any rate, here's the current state of the car-sharing art in Philadelphia as seen through the eyes of Zipcar.