I remember watching the show as a kid.
Closer to the present, I recently heard a segment on “This American Life” (one of the more popular PRI radio shows on NPR). They even have the episode archived so that you can listen to it through RealPlayer.
Speaking of Mister Rogers and NPR, “Morning Edition” did a segment today and has posted the transcript with a few related links on their website.
You can read more about Mister Rogers’ philosophy from misterrogers.org.
Also, if you happen to have kids who watch the show, be sure to read PBS Kids’ helpful hints for parents.