Mary Cheney, former head of broadcast at Bartle Bogle Hegarty/New York, has joined Leo Burnett USA as a vice president-senior producer. The move takes Cheney back to her native Chicago. ... Tim Vaccarino and Joe Fallon -- a former Arnold Worldwide associate creative director and senior copywriter, respectively -- have joined Boston's Modernista! as associate creative directors. ... Rachel Newell, formerly of McDougall Creative, has joined San Francisco agency Attik as new business manager, a new position. ... Colorist Sean Coleman, formerly of Rushes/601 in Los Angeles, has joined Company 3 in Santa Monica. ... Assistant editor Cindy Nielsen has been promoted to staff editor at New York's Chinagraph.