Chick-ago

Anybody ever been to Chicago? What's fun to do there?* Other than the Museum of Science and Industry, that is, cuz I'm a huge nerd. The Chicago Tourism site seemed difficult for me to navigate, with some links believing themselves to be executable files, and everything either having already happened in 2006, or will happen, but not in May (when I'll be there).

Suggestions?

*Other than drinking. This is partially bizniss.