As the saying goes, "Out with the old and in with the new." ADAPTING SUBURBS IN THE 21ST CENTURY at the Museum of Design Atlanta shows that you can have a little of both. The exhibition features 10 suburban retrofitting projects, which redesign and redevelop existing underperforming neighborhoods rather than build new ones. The projects are happening all around the country, including right here in Atlanta, led by Georgia Tech architecture professor Ellen Dunham-Jones. In conjunction with the New Urbanism: Rx for Healthy Places conference May 19-22. Through May 29. Free-$10. Opening reception May 7, 6 p.m.; Tues.-Sat., 11 a.m.-5 p.m. Marquis II Tower, 285 Peachtree Center Ave. 404-979-6455. www.museumofdesign.org.