Instant Messaging is rapidly becoming accepted in business community as a viable communications tool and process - it's faster than e-mail, free on client side, even a novice user can easily grasp interface in just a few minutes and it enables remote workers and business partners to "talk" and share files and information effortlessly using in-place infrastructure of internet. Its mushrooming in popularity too - according to IDC, corporate and general business users will jump from 5.5M in 2001 to close to 200M by 2004. What are some of pitfalls and concerns you need to have when assessing and integrating Instant Messaging ("IM" another biz acronym) with your business processes? Be aware you are sending clear text messages over public Internet - so all IM technology is inherently insecure. Privacy issues can also be raised - these messages are typically archived via IM servers of company whose services you are using and can be made public at a later date. Anyone with a network scanner may have access to and be reading your messages and if your are downloading files, you need to ensure your anti-virus software is setup to scan these files when you open them.
One of biggest pitfalls of technology and process is that it adds another communications layer to your busy day - but you can offset this by selecting or filtering who you communicate with at any point by using IM interface to block all or selected individuals from "seeing" you when you are online.
Finally, like all things in today's computer industry (or many) each of Instant Messaging vendors are trying to build applications which don't integrate with other (no surprise here - arrogance has not faded away in business community!). So, you need to assess installed base of market leaders and make a decision on which company's product you want to utilized - my recommendation would be to review Microsoft's or AOL/Time Warner's products - their installed bases are in 200 million users plus when combined (these numbers include consumer and business usage) and they both work well and have user interfaces that are intuitive.
There is one alternative company that is solving "IM Tower of Babel" issues and claims to integrate well with all proprietary apps by utilizing XML technology, Jabber, Inc., www.jabber.com So, if interoptability is important to you then I would recommend assessing their products.
Most of IM providers including Microsoft are integrating voice communications with their IM clients - you may be able to bypass your local telephone carrier at some point using this technology, but don't bet on it anytime soon - all of those lobbyists here in states need to keep generating fees on behalf of their telecom clients in Washington D.C. We use Microsoft's IM product and we have upon occasion utilized voice and video features (you must of course have a multimedia setup for your PC and camera) and they do work. Although video quality is a little jerky and voice is akin to old Citizens Band ("CB") radio - your Internet connection impacts quality of both.