Santiago Calatrava, the Spanish architect who designed the bird-like addition to the Milwaukee Art Museum, this week unveiled his latest design for a proposed 150-story condominium building in Chicago. To see the rendering go to: http://chicagobusiness.com/cgi-bin/gallery.pl/RealEstate?date=2007-03-27&galleryImage=. The 1,200-unit condominium building would be built by Irish developer Garrett Kelleher. It would be the tallest building in the nation and would be located west of Lake Shore Drive along East North Water Street, near Navy Pier. Kelleher is hoping to obtain city approval and begin construction in May.