Enthusiastic users of these short text messages include the monolithic U.S. Navy, which has loaded Lotus instant messaging on the computers of every ship at sea. But you don't have to be huge to appreciate the technology. Ketchum Public Relations in Atlanta is also a committed user.

Vanessa Lindberg, Ketchum senior account executive, says that when her 100-person office adopted AOL Instant Messaging, she found it intrusive. "I couldn't even go to the bathroom without coming back and finding seven new IM windows." Six months later, she wouldn't be without it because it's so efficient. "I'd be in withdrawal," she says.

John Patrick, IBM's vice president of Internet technology and author of Net Attitude, says nearly all the company's employees use IM. "We went from zero to 250,000 users with no help desk, nothing official. Today if we turned it off we'd have a mutiny. It's fundamental to people in IBM."

Instant customer contact
Tech-dependent companies aren't the only ones embracing IM. Businesses with only a passing e-commerce connection have learned it can afford useful customer outreach.

American Greeting Co. has introduced important date instant messaging for customers. Realtor Re-Max allows its agents to IM customers when their ideal home comes on the market.

Television and online marketer QVC uses it to solve customer problems. Stephen Hamlin, vice president operations of QVC, says most of its customers still have only one phone line. Instant messaging allows the company to help online buyers without forcing them to sign off and pick up the phone.

Raj Goel is chief technology officer at Brainlink International in New York City, a technology services company that relies heavily on instant messaging for business communications. He explains why it's so vital to his 22-person company:

• It's the best way to make sure no one ever has to repeat an answer to a question. This is especially helpful when employees are dealing with complex technical issues or staffers need to share URLs.
• It keeps employees' e-mail clients from being swamped with simple questions.
• It keeps an open work environment quiet.
• It allows those involved in complex projects to give their answers to pressing questions at convenient stopping points vs. interrupting their train of thought.
• It makes dealing with a distributed work force (telecommuters, those on business trips) more efficient.
• It's much easier than audio conferencing if several employees need a quick discussion. With IM, they can set up a chat room -- for free.

Sales tool potential
Instant messaging also can be a great sales tool if used judiciously.

Pat Fallis, executive producer for Practical Synergy, an opportunity development agency and marketing company in Burbank, Calif., suggests linking IM to your customer database. Then you can send out IMs to alert customers to things like price cuts. "It's faster and less disruptive than a phone call."

Fallis also suggests that service people make themselves available for instant messaging during key times. A doctor (or a plumber, for that matter) might advertise a window of IM opportunity to make an appointment or ask for a prescription renewal.

To make things go as quickly as possible, he says preload responses. Just paste and send. If you need a record, save the IM logs.

IM options
The Big Three in instant messaging are America Online Instant Messenger, Yahoo Messenger and Microsoft Messenger. Compatibility remains a big issue; none of the platforms plays well with the others. IBM's Patrick insists this is a temporary problem that business and consumer demand will solve.

In the meantime, pick one. If you need to be available to users of all three, look at FaceTime Communications software that acts like an old-fashioned telephone operator. It receives IMs of all sorts and sends them back out to recipients you specify in the proper format.

FaceTime also can recognize keywords, so an instant message that arrives at your company can be automatically distributed to the right person. For instance, in the case of a plumber, a message that said sewer and emergency could go first to the sewer specialist on call.

Barry Shurtz, director of marketing for FaceTime, says the cost is based on a variety of things, including whether you buy the software or the company hosts it. But expect to pay at least $200 a month.

Is it secure?
Security is another troubling issue for businesses contemplating instant messaging.

eFront learned the hard way. The company runs a network of affiliate Web sites that agreed to pool traffic as a way to command higher advertising rates. Rate discussions were all carried on via instant messaging. Somebody, apparently not enamored with the way business was being done, posted a log of the discussions on the Internet. eFront referred the matter to the FBI, and the top executives involved resigned.

The obvious answer to security concerns comes from Thubten Comerford, CEO of the Colorado-based network security firm White Hat Technologies: "Don't say anything via instant message that you don't want the whole world to read."

Comerford's 25-person company has salespeople and technicians spread out all over the country and uses AOL IM constantly.

"We have a secure server that everybody can access, so if we need to talk securely, we can and do," he says. "But for everyday business, like 'How'd the sale go?' we use AOL and we don't worry about it."