Buried Treasures?

It's a new semester, so I have new colleagues and new students, a lot of whom are new to Pittsburgh. A few of them know about this blog, so they ask me: What are the hidden gems of the Pittsburgh region? Not the great places to go, to eat, to shop that represent the best or the best-known of the place -- but the neat and cool and interesting and fun stuff that's a little bit off the beaten path. Even I know enough to recommend Pamela's and DeLuca's and Enrico Biscotti (which, by the way, may be the single greatest foodstuff produced in the city. But I digress.). But I don't have the depth of knowledge to be as helpful as I'd like. Among the lesser-known destinations, what do you recommend?