I did the Ducky tour in Seattle as well but the one in Pittsburgh was much better and cheaper. $20 for an hour tour of the city on a bus that turns into a boat as it plows into the river. Our guide was very helpful, funny, and knowledgeable of Pittsburgh. Mind you, some of his jokes weren't funny, they didn't "quack" me up, but he was still very entertaining.
The tour took you through the entire downtown and gave you good snap shots of remarkable architecture and good views of PNC park and Heinz field. Along with the tour came interesting historical facts of Pittsburgh and made you appreciate the city and what it has to offer. There is a lot of history there. I would definitely reccommend this tour to any out of towners that are in Pittsburgh for a short time and want to get a feel for the city.