St. John & Partners has added Shawn Parks as associate media director at its Jacksonville, Fla., headquarters. Parks will direct the agency's Clearwire and Vistakon media planning teams. He previously worked as a planning supervisor in the Miami office of Chicago-based Kelly, Scott & Madison. Before that, he was associate director of strategy for Cingular Wireless at OMD in Atlanta. The shop has also hired Sherrie Holliday as a senior media buyer. Holliday will negotiate and execute television and radio buys for the Southern Ford Dealers, Zaxby's and Clearwire accounts. Previously, she was a media supervisor at Keating Magee in New Orleans, overseeing TV and radio buys for Cox Communications and print advertising for the Jackson Brewery, Decatur Hotels and One Cleaners.