What: A few interesting sites that have found a way to use Google Maps for niche interests, ranging from environmental concerns to travel to panoramic photography
DCF: The cool factor here varies by concept...
Flood Maps - View a map of the new coastline for sea level increases ranging from 1M - 14M. Scary.
Wines and Times - While this site leaves much desired from a design perspective, Wines and Times offers a robust listing of wineries across the United States, as well as their hours of operation.
Panedia - Scrolling panoramas of over 7,000 locations (defaulted to Australia - love it.) Similar to Street View, but a more smooth and visual experience.
mezzoman - Type in two addresses to get a suggestion of places to meet in the middle
Broadway2Day - See a map of Broadway shows filtered by date and genre...especially helpful for hunting down rush tickets!