I have seen Present.ly (www.presentlyapp.com) quite a few times at tradeshows pushing their corporate micro-blogging platform. Think Twitter for the enterprise. It looks to be pretty popular though I cannot imagine what companies want with such a service…
If your company is using Present.ly, I just heard that there is a free open source client for the BlackBerry that is now available at the link below created by Brendanlim.
Let me know in the comments if you use it!