Twitter on your intranet: 17 microblogging tools for business | Enterprise Web 2.0 | ZDNet.com

Nice round up of options for enabling enterprise-like Twitter functionality. A couple of the options seem like a force-fit.

The tool I have experience with is Yammer, and I've been very impressed. I didn't find it that compelling in the beginning, but the more people in your enterprise that start using it, the more value starts to appear. This is probably true for the other tools in the round-up as well.