We initially used a commercial product that was cutomized for internal use. I guess it was a success as we have moved to MS LCS, again customized to our specs. All that is allowed is text messages and desktop collaboration. Even urls are converted to text.
One thing to note is that NOTHING is saved under the new system, it is just a comms link.

There was a note earlier saying that once it was digital it needed to be saved for 7 years, I wonder if they have IP phones.

This system can be a great aid when working on large comms problems - quite often in parallel to the monster conference call which has too many chiefs wanting airtime. The work gets done while they rant and rave. It does help to have a large desktop screen area for many more windows tho.

My workgroup has members spread across North America, this really helps communications with them (even if they are in the same office)