There's a pretty interesting startup called Flocations. They're a TechStar startup from Singapore. They allow you to visualize where you can fly to based on your departure airport, budget and dates. It's a travel inspiration tool similar to KAYAK Explore, "see where you can go for how much".
It's pretty neat but isn't really working for most airports. It's a good tool to use once they add more airports and make the flight searches more usable in terms of speed and bugs.