Cisco System has figured out how to improve business prosesses and productivity using social media tools. Thier CIO, Rebecca Jacoby has led the charge. "... implementation of the following platforms: a dynamic company directory, à la Facebook, that allows employees to collaborate and locate subject-matter experts; a video wiki, à la YouTube, that lets workers post searchable video and audio messages; a company- wide wiki, à la Wikipedia, that supports a vast glossary of company-related knowledge; another wiki that captures business-related ideas; and a portal that explains how best to deploy all the aforementioned technologies.
Some would consider these social media or Enterprise 2.0 projects. Jacoby, a 14-year Cisco veteran, is more likely to characterize them as business process improvement projects, supported by some new collaboration tools. How Cisco Uses Social Media by Elizabeth Bennett"
What's so great about social media tools is that most of them are free. You can use them as a service or download them so that you can install and modify them yourself. Heads up - some of these tools are powerful and can be extended to do almost anything.
"This is one of the very best list of its kind where you can find the simplest online tools that would be helpful for business purposes. You can also use them and will love them whether you are an office worker, a manager, a supervisor, a student, a home user, freelance designer/developer etc. 21 Free Business Web Apps That Can Make Your Lives Easier"
Most of the social networking, community, and portal stuff is built on top of open source software (OSS) which includes content management systems (CMS). CMS's range from very simple, wordpress to more complex ones like plone.
Here is, "20 Promising Open Source PHP Content Management Systems(CMS)" from webdesign booth to get you started.
We prefer to use Drupal, Wordpress, Joomla, and on the CRM side, CiviCRM and SugarCRM for mosdt of our client projects. These applications work great for the markets we serve.
What social media tools are you or your organization using?