I’d also add that OneBusAway has a new Explore feature that not only let’s you find transit travel times from a particular address, but also let’s you search for local restaurants, parks, or whatever you are interested in within your specified transit range.

http://onebusaway.org/explore/onebusaway/

For example, for Mexican restaurants less than 20 minutes from my house by bus:

http://onebusaway.org/explore/onebusaway/…