Should have mentioned earlier. Take the double-decker sightseeing bus. Stops all over downtown at architectural/other points of interest. Wrigley bldg, Sears Tower, Hancock bldg, museaum campus, etc. Can get off on as often as you like, and has knowledgeable tour guide narrating. Can easily hit al the highlights that way. Don't think it goes to McCormick or Science & Industry though.