Consumer instant messaging (IM) products may have crept into companies on the sly but their booming popularity has led to a host of vendors loudly knocking on companies' doors, offering to provide IM products dressed for business.At the front of the line are consumer IM powerhouses Yahoo, Microsoft and America Online, which have all announced enterprise IM plans in recent months, but they face competition from other technology firms lining companies' waiting rooms with their pitches for the corporate IM market.Nowhere was this more clear than at the Instant Messaging Planet Spring 2003 Expo and Conference in Boston earlier this week, where start-ups and industry stalwarts alike hungrily gathered in hopes of getting a slice of the corporate IM pie.The incentive was clear. The steadily growing IM market is expected to balloon to close to $800 million by 2006 according to some estimates, and growth of IM use has been tracked at a frenzied pace, with Yahoo alone reporting a 50% increase in monthly usage since December 2001."This is an overwhelming phenomenon," Yahoo's Senior Vice President of Enterprise Solutions Steve Boom, told the attendees during his keynote address Monday.In addition to the leading consumer IM vendors, technology stalwarts such as IBM and Oracle are also crowding the corporate IM market. Oracle is planning to highlight enterprise real-time communication capabilities in its forthcoming collaboration suite, according to Anindo Roy, the company's director of software development for collaboration products.Oracle intends to be a "major player in the real-time space," Roy said.While the leading consumer IM providers have the advantage of a large, existing user base, players like Oracle and IBM are banking on their enterprise software experience. Lotus' Sametime collaboration software has already made clear inroads into the corporate market and has even recently announced that it will be working with AOL to provide tighter integration of their corporate IM products.Mobile providers are also jumping into the fray. Sprint, for instance, has built a strategy around using IM as an application to deliver enterprise services over mobile devices. The company's recently unveiled Enterprise Application Messaging platform allows users to access corporate applications through the buddy lists on their mobile devices, among other capabilities."Companies are going to realize, 'Holy cow, this is a powerful technology,'" said Bruce Friedman, Sprint's group director of Mobile Computing Services.And Sprint is not the only mobile player banking on the power of IM. Telefonaktiebolaget LM Ericsson announced Wednesday the creation of an interoperability test program for IM and presence services, and that Motorola, MessageVine and Sony Ericsson Mobile Communications, among others, have agreed to join.While the bigwigs plot their moves, there is no lack of niche players ready to dig their heels into the market. Take Imvector, which is aimed at creating a network to deliver authenticated commercial instant messages, as well as a name registry that provides security for identities.The Washington, D.C., company has already quietly rolled out its services, with plans to officially launch early next week.Imvector's advantage, according to company CEO Todd Tweedy, is that it allows separate IM providers' "silos" to exist and still have secure communication between users.Vendors like Imvector may have the ability to fill in the gaps left by major IM providers when the market further matures. Even Microsoft Product Unit Manager David Gurle admitted at the conference that his company's upcoming "Greenwich" enterprise instant messaging offering would benefit more from being based on an IM "clearing-house" business model rather than the federated model on which it is built, allowing certain business partners and customers access to its network.While industry watchers will have to wait to see how the market shakes out, one thing that is clear now is that there are high hopes for enterprise IM."IM has fundamentally changed the way we communicate," Yahoo's Boom said. It may also change which vendors users choose.