I removed this from one of the posts regarding the Halloween storm for two reasons; I didn't want to hijack the original thread, and I wanted to flesh out things more.
Route 21 is a good route for those who use the Orange and Red lines and don't want to loop through downtown. On the off-peak and the weekends, Route 21 does run consistently (albeit infrequently; on Saturdays it's every 40 minutes and Sundays it"s every hour). Read more.
Adam had a post regarding the Boston neighborhood markers (http://www.universalhub.com/2012/what-happened-mar...) and I had mentioned about the old street signs that still exist in Boston, such as the one on the corner of Temple and Baker Street that still exists.
Over the past few months, however, I have been using Google Maps and Bing Maps to find pictures of the signs that still exist. They are divided into sections; simply click a point on the map, and select Street View to see the image.