We pretty much did the same as Rodney during our day trip on Columbus Day. I had my two daughters (13 and 10) with me, so we shopped, ate lunch, saw a movie. Pretty much filled the day.We did have breakfast in Seegers Union. It was fun to kind of fade back and observe a little bit of a typical college morning.
Check the theater/music schedule. Maybe you can catch a performance while you are in town. Don't know if your D is interested in performing arts, but the programs are first rate and the kids put their whole heart and soul into it!
Let us all know what other spots you find. DS is heading back in a few weeks for his audition with the theater department. I'm not sure I can handle another full shopping day!