I think we all use co-blogger Frank's example about the "free bikes" at Berry College in our classroom discussions on private property. An interesting project would be for students to compare the predicted results of a Berry Bike experiment with this:

"TH!NK about is a separately franchised car sharing entity and a sustainable alternative to personal car ownership. TH!NK about will provide a fleet of TH!NK citys, centrally placed at a number of unmanned stations around the city. The vehicles will be available for rental on an hourly basis. Customers book online, via their mobile phones or simply pick up a TH!NK city at the nearest station. A personal membership card, equipped with cordless technology (RFID) will provide access to the vehicles. Drivers return their TH!NK citys at the agreed time and receive a bill at the end of the month."

I've been on the lookout for itty-bitty cars since seeing the smart fortwo in Germany last year. Of course, the TH!NK about campaign does try to infuse property rights, since the cars won't be free. Still, it will be interesting to see the results.