The new iPhone app, called Bluebrain (Central Park), is literally a sound track to Central Park. Turn the app on, walk into Central Park, and the app uses your location to play different types of classical music as you walk around. The music is apparently synced with different locations, so as you approach different statues, paths and landmarks, music that corresponds with each landmark begins to play.
This New York Times article, which does a significantly better job explaining the app than I do, gives the following example; "At the Bethesda Fountain a string quartet plays a hopeful march. The Kerbs Boathouse, with its tranquil pond full of model sailboats, triggers a soothing Pachelbel-like motif with a descending bass. Strolling across Sheep Meadow you hear a pastoral piano theme with a bubbling undercurrent of electronic arpeggios." Best part? This app is free! I have already downloaded it on my phone and will use it the next chance I get to stroll in the park (sadly that will most likely not be until next weekend). This is a definite must-have app for all New Yorkers (and anyone planning to visit).