Here in NYC, we've been hearing a lot about rat problems in restaurants. That's a problem that the guys behind Ratatattle are trying to combat; they've created a real-time Google Maps mashup that lets users report on which dining establishments in their cities have had issues with rodents recently. It's completely user-generated: if you happen to see a rat, just head to Ratatattle, hit the "tattle" button, and you'll get a series of prompts for entering the dining venue, number of rats, size of rats, and whether or not they were anywhere near the food.
It's a great resource if you're new to a city and are concerned about the levels of rodent infestation--the directory is very detailed, right on down to letting you know whether it was the KFC or the Taco Bell in a KFC-Taco Bell hybrid where the rats were spotted.
Ratatattle is still in beta, but the creators have planned a whole host of new features for the full version, due to launch in early June. They've hinted at real-time tracking of "ratspots" within cities like San Francisco, New York, and Seattle. Additionally, there are additions in the works that will incorporate embedded videos (for when you catch that sneaky rat on your camera phone!), a Digg-like "RatRank" of the scariest-looking rodents spotted, as well as a social network for "rat-aware Internet users."
They're even indicating that they may expand to include mashups to track the presence of other pesky animals, like cockroaches, moles, and feral pigs. Unfortunately, such offshoots won't have the rhythmic ring of "Ratatattle," but I still think that it's important to know which regions of the country have feral pig infestation problems. Talk about an untapped niche of Web 2.0.