Mapnificent

Just came across Mapnificent, a service on top of Google Maps to aid in using public transit to get around.  It's exceptionally easy to use and quite intuitive, and to say the least, after 30 seconds I was already impressed with its ability to display the estimated area that you can cover within a given amount of time using a configurable combination of public transit, walking, and biking.

Plotting 15 minute reachability zones from two separate locations in night mode.