It's one of those things you have to do at least once, but make sure you bring a good camera because the views at the top are spectacular.
I forgot mine and had to settle for my camera phone which does not have good megapixel, but it did the trick.
The Monongahela Incline is the oldest continuously operating cliff railway in the United States and it's worth checking out. It holds about 17 people and cost $2.75 round trip to ride it. (Free for seniors) It's a short walk from the Smithfield Street Bridge.
There are several eateries at the top of the funicular and the Station Square, and restaurants are located at the bottom.
The best part is there is free WI-FI at most of the restaurants down there.