RIM and Lotus are always talking about the social features they are adding with their new BES server editions. They sound very cool, but most companies do not use Lotus… When we mentioned Present.ly previously, Deacon let me know that there is a practically free alternative called Yammer. When I say practically free, I mean that it is free unless your company wants to administrate it, which costs $1 per user per year. Otherwise you can create the social network yourself for your company for free.
Yammer is a combination of a social network and discussion board that throws a bit of Twitter-like functionality into the mix. It is intended to be private so only people in your company with a company email address can join your network. Their BlackBerry client gives you access to that information on the go, but I have not had a chance to try it myself.