O'Dwyer's today published its annual ranking of technology PR firms. Edelman, Waggener Edstrom Communications, Lewis PR, APCO Worldwide and Racepoint Global lead the list of 76 agencies. 

O'Dwyer's Ranking of Technology PR Firms 

O'Dwyer's Ranking of Independent PR Firms - March 3, 2014

Healthcare and financial categories will be published March 17.