MLB fans use At Bat app to purchase tickets and store them in Passbook

GigaOm reports that beginning with the 2013 season, the Baltimore Orioles, Chicago Cubs, Detroit Tigers, Milwaukee Brewers, Minnesota Twins, Oakland Athletics and Pittsburgh Pirates will join the San Francisco Giants, New York Mets, Boston Red Sox and Kansas City Royals in supporting Passbook tickets. Three additional teams have signed on, with an official announcement coming soon, the MLB said.