I wanted to know what was half an hour from my house, so I made Triptrop. Put in an address and you get a map of how far everything is away from it. 15 minutes, forty minutes, two hours - all set up with nice little colors. That's pretty easy, I think.
Triptrop can help you find a convenient place to live. It's also a nice way to tell your friend to stop inviting you to the purple part of the Bronx, or to prove that the G isn't actually that bad†. I don't have to use Hopstop on 40 different addresses before I figure out where I'm going anymore.
Learn more over here.