Finding a parking space, and more.

Roadify.com, a parking, traffic and public transportation real-time information application for mobile smartphones, won a $10,000 prize from New York City for the best new app.
Not only does it help you find a parking space, get real time traffic and transit times, it also has a social component as it gives you crowd-sourcing social updates from on-the-spot commuters. The BigApps competition challenges programmers to develop mobile software applications that encourage users to access a wealth of publicly available city data. The real prize in the contest is the attention that venture capitalists give to the winner.