Instant messaging continues to grow as a medium for online communication, according to details of a study released by America Online on Thursday. Instant messaging is up 19 percent, and 38 percent of all users say they now send more IMs than e-mails.

The survey also found that one-third of users connect to instant messaging networks through their mobile phones. This is nearly twice the number recorded last year, when only 19 percent said they used such services, and over three times as high as in 2003, when the number stood at 10 percent.

IM usage is increasing in popularity at work as well, with 58 percent of professionals using it to communicate with their co-workers. Half send messages to get answers and make business decisions, with a little over a fourth having used IM to communicate with clients.

Some turn to instant messages to avoid difficult conversations; one in eight have used it in place of a face-to-face meeting at work.

"Instant messaging is a part of everyday life, with more and more people using their IM service as a starting point for all communications, from sending mobile messages to friends on cell phones to placing VoIP-based phone calls," said Chamath Palihapitiya, AIM and ICQ's vice president and general manager.

This trend is evidenced by increasing requests for more feature-laden messaging clients. One in four would like live streaming television or music on-demand included, while one in five would like to see video on-demand or voice over IP (VoIP) services.

Moveover, one in eight IM users would replace their landline phone with an instant messaging service that features VoIP capabilities.

According to the survey, Miami, Florida is the top market for instant messaging. Also, AOL found that New York City IM users are most likely to maintain multiple screen names, while users in Tampa most often use IM at work.

In Seattle, users are most likely to say things in work-related IMs that they wouldn't in an e-mail message.

The survey polled 4,032 respondents age 13 and older from September 16-26. Thursday's survey was the third annual installment of the questionnaire, which looks at trends in instant messaging usage.