From the Wikipedia:
"Micro-blogging is a form of multimedia blogging that allows users to send brief text updates (say, 140 characters or fewer) or micromedia such as photos or audio clips and publish them, either to be viewed by anyone or by a restricted group which can be chosen by the user. These messages can be submitted by a variety of means, including text messaging, instant messaging, email, MP3 or the web.
The content of a micro-blog differs from a traditional blog due in that it is typically more topical, smaller in aggregate file size (e.g. text, audio or video) but is the same in that people utilize it for both business and individual reasons. Many micro-blogs provide this short commentary on a person-to-person level, or share news about a company's products and services.
The most popular service is Twitter, which was launched in July 2006." (http://en.wikipedia.org/wiki/Micro-blogging)
- List of internal microsharing tools for business at http://pistachioconsulting.com/list-of-internal-microsharing-tools/
- List of enterprise microblogging tools, at http://www.web-strategist.com/blog/2008/09/08/list-of-enterprise-microblogging-tools-twitter-for-the-intranet/
- Directory of microblogging and realtime messaging tools for E-Learning, at http://c4lpt.co.uk/Directory/Tools/microblogging.html