You may or may not be familiar with Twitter. Twitter is what is called a micro-blogging site. It allows you to post short messages that answer the questions – what are you doing? You can access twitter via the Twitter web site, your mobile phone, or a number of desktop applications. The messages called tweets are received by your followers and you receive messages from those that you have chosen to follow.
Twitter does have some shortfalls. It is by no means private which rules it out for business. Anyone can choose to follow your twitter activity. Twitter also does not have function to create groups.
Yammer answers these problems. You sign up for Yammer using your corporate email account. The only people allowed to follow you are those with the same email domain extension such as yourcompany.com. You can also create groups and easily follow threads. Yammer is accessible via their web site, applications for various smartphones, and standard cell phones. They also offer a desktop application.
The Yammer web site has a great introductory video that demonstrates how to use the site in real world applications. The application is free unless you want more advanced features.