With the Twitter IPO on the horizon, I thought it would be interesting to check out how many of the CEO’s and heads of the Top 100 PR Agencies tweet regularly. Ultimately “regularly” ends up being a bit subjective, but as long as it looked like they were tweeting at least once or twice a week, they made the list.

A few tweet repeatedly throughout the day, while others seem to have spurts of tweeting over the course of the month. Most seem to maintain their own accounts, while others look like they might be kept updated with some staff help.

In any event, here are the 24 that we found.

If you happen to know of a Top 100 PR firm CEO who should be on this list but isn’t, just let us know.

5W Public Relations Ronn Torossian
Access Communications Susan Butenhoff
Airfoil Lisa Vallee-Smith
Akhia Jan Gusich
Allison+Partners Scott Allison
APCO Worldwide Margery Kraus
Atomic Andy Getsey
Kaplow Liz Kaplow
LEVICK Richard S. Levick
LEWIS PR Chris Lewis
Lois Paul & Partners Lois Paul
Makovsky Ken Makovsky
Mitchell Communications Group Elise Mitchell
Ogilvy PR Worldwide Christopher Graves
PAN Communications Philip A. Nardone, Jr.
PMK-BNC Cindi Berger
Porter Novelli Karen van Bergen
Racepoint Group Larry Weber
Schwartz MSL Bryan Scanlon
SHIFT Communications Todd Defren
Text 100 Aedhmar Hynes
W2O Group Jim Weiss
Wagstaff Worldwide Mary Wagstaff
Zeno Group Barby K. Siegel