Love it or hate it, instant messaging has become a necessary tool for PR pros. When waiting 20 minutes for an e-mail response just won't do, IM is there.

Jason Mandell, principal at San Francisco agency LaunchSquad, says his Mac-centric office uses the AIM/iChat software and Skype to communicate with some clients.

"We are primarily using it with briefings with analysts and reporters," Mandell says. "We can give [clients] ideas on how to answer a question, or guidance."

Chris Blake, account director ...