Here in New York City, there is an incredibly popular burger stand in Madison Square Park called The Shake Shack. It's one of the touchpoints for Silicon Alley, and a great meet-up spot. The problem is that its usually insanely crowded, with an hour-long line stretching well across the park.
Not to be defeated, Silicon Alley geeks created the Shake Shack Twitter Bot, which serves as a sort of chat room for people to report wait times at the Shake Shack. It's a few dozen lines of code that leverages Web 2.0 technology to make the city smarter, more efficient, and more fun.