“The First Annual Google Programming Contest, announced about 4 months ago has ended. The winner is Daniel Egnor, a former Microsoft
employee. His project converted addresses found in documents to
latitude-longitude coordinates and built a two-dimensional index of
these coordinates, thereby allowing you to limit your query to a
certain radius from a geographical location. Good for difficult
questions like “Where is the nearest all-night pizza place that will
deliver at this hour?”. Unfortunately there is no mention whether this
technology is on its way to the google labs yet. There are also details of 5 other excellent project submissions that didn’t quite make it.” [Slashdot]

It’s worth checking out the honorable mentions to some great ideas (and code for sure).