My sister Karen went to this the first time through when it was in L.A., and she raved about it.  Now it's making a second tour, and will be in Chicago later this month through the end of April.  It's called Body Worlds, and is a display of cadavers that have been preserved using plastination.  Once you get over the fact that there are a lot of human bodies that have been posed, sometimes in strange positions, it looks to be an extremely enlightening display of the human body, and how it works.  I do believe I'll have to make it down to Chicago to see it.