If you ride bikes in the neighborhood, whether yours or a shared bike, here's a great new resource. It's called BikePlanner, and it's a site where you set your start and end points for the ride, prioritize whether you prefer quick, flat or bike-friendly routes, and select if you're using your own bike or a shared bike, and the system makes a route for you. It's based on OpenStreetMap, which is an editable online map, so that means you can also add new bike lanes and such to improve the accuracy of the routing.
The project comes from OpenPlans, and it looks like it's only for DC and the surrounding area. Here's a bit more.
Pretty awesome stuff, take a look and try it out. Above is a trip I chose from about DCUSA to the Washington Monument, using a route that's mostly bike-friendly and flat.