In a patent filed just today, Apple planted a flag in GPS-based "Parking and Location Management Processes and Alerts". Everyone, quick, check for iValet trademarks!
Of course, it's just a patent, which means we're some time away from reaping its proposed rewards. But if Apple ever does get this up and running, it'll provide information like where the nearest taxi is, parking lot availability and cost, and when it's OK to park on restricted sections of the street.
It looks like the system will also take into account user preferences, giving different options based on how far you're willing to walk and your weather tolerance. I can't wait to see it once it's fully integrated on the iDashboard of my iSedan. [US Patent Office via GoRumors]