My daughter and I just attended this exhibit at Chicago's Museum of Science and Industry. If you like HP (movies or books) this is a great opportunity to see the major costumes and props and some magical creatures up close. Some of the costumes were incredibly detailed while others (Snape's for instance) were very "working class/every day sorts of clothing" as if they were bought at the Wizarding equivalent of Sears or JCPenny. The props were wonderfully detailed and included wands, quidditch equipment and even beds from the Griffindor dorm room that Harry and Ron shared. The exhibit takes about an hour to see (audio tour seemed longer).
http://www.msichicago.org/whats-here.../harry-potter/
If you have a membership at another science museum, call MSI to see if it's on their reciprocating general admission list. They give you the "member" price on the exhibit tickets, as well, if it is.
Harry Potter–The Exhibition
