Not much need for this here in rural Iowa. But if I lived in one of the hundreds of U.S., Canadian, and European cities covered by this app, I'd definitely give it a try. PIM (free) lets you find, reserve, and pay for a parking space via your iPhone. It has information on over 16,000 parking facilities, including rates, hours of operation, entry points, and facility type. It even helps you navigate to the facility.