Social Source Commons

Amplify is the social way to blog, combining social networking features with blogging. Amplify autoposts to Twitter, Facebook, Posterous, Tumblr, Friendfeed, Delicious, Diigo, Plurk and more

Linked to salesforce this is essentially a secure way of communicating within the office.

Combination of twitter and chat room but access is limited to people with a verified email address.

Social-bookmarking website

Note taking application.

Feedly is a news reader for creative minds, a simple and elegant way to read and share the content of your favorite sites.
Based on Google Reader and Twitter.

A website that helps manage multiple Twitter profiles, pre-schedule tweets, and measure your success.

Online petitions, with support for custom-design petitions, customized question list, filtering of duplicate signatures, and access to real-time data.

Easy-to-use interactive tool for exploring your Twitter network. Discover which people interact the most and what they're talking about.

Tools to enable organisations to communicate with their stakeholders.
Organisations are able to carry this out in a number of ways using social media tools including text, video, audio and social reporting.

Rapportive shows you everything about your contacts right inside your inbox.

Upload and share powerpoint presentations.

A search engine powered by tweets

Twitalyzer is an analytics platform for Twitter, with both free and three levels of paid services. Paid accounts add automation, export, support for multiple accounts, and the ability to deeply analyze any Twitter user.

Twitter is a global community of friends and strangers answering one simple question: What are you doing? Answer on your phone, IM, or on the web.

Advanced Twitter analytic system calculates daily tweets, users who are retweeting your messages, and their unique reach

Flexible open-source content management and blogging software with an active user and developer community and a wide variety of plug-ins or extensions available.