If only this place was in San Francisco! The 61C Cafe was my favorite coffee shop/study place when I was in college. It is named after the bus route which stops outside the front door (the 61C bus route...).
They have a large selection of coffees and loose-leaf teas. They have lots of great home-made baked goods. The Ginger Snap cookies are the best I've ever had. It is the only coffee shop where the DEFAULT is "for here" mugs...people who get drinks "to go" are looked at strangely. Go with your laptop or a newspaper and get out of the freezing (I mean FREEZING!) cold of the Pittsburgh winter and enjoy this place.