IRC — We have used a dedicated IRC server from the start, and it helps out tremendously when people use it (the Linux folks use it heavily), but it doesn't entice a vast majority of the employees. It's used mainly for BS'ing, but also becomes a very important tool when things are awry.
Facebook — Most people are on Facebook, but obviously there are details about the company that cannot be discussed, which is an issue since most of these profiles are public and it is a somewhat common practice to be friends with some clients.
Exchange 2007 — E-mail is the main source of communication, but can't it be painful sometimes? Everyone on the IT side receives alerts about tickets and other automated checks of systems. On any given day I generally receive 100+ alert messages. When we're not reading our filtered alerts into specified folders, general discussion about projects and fixing issues usually is anywhere from 20-60 messages a day. Quite honestly, I'm sick of e-mail and don't wish to get any more of it. I know a lot of you feel the same way.
Phone — Just using the ol' phone is the other primary way of communicating with the customer, but not ideal for communicating ideas with others at the same time. We have bridges, but they're only used for conferences with customers.
Company Meetings — We have these a few times a year. They're fully catered and consist of introducing the new people, talking about new contracts, and congratulating others on successful implementations . These generally last about an hour or so at the end of the workday. Unfortunately dedicating to these meetings is not the easiest on people's schedules, especially the help desk, and is not an open forum.
There are forms of collaboration that I have been thinking of. To list some, there is phpBB, Elgg, Jabber (discussed a few times before), and Google Wave (hard to push currently). Personally I think that a closed social networking platform would be ideal, where ideas can be posted and read at any time. Tell me what you think of these ideas, if there are more suitable solutions, or what you use at work."