Just like how we have Facebook Share buttons, Microsoft has announced Yammer Share buttons for websites. With the Yammer Share Button, you can share useful web content directly into your network to help your colleagues get the most out of Yammer. Select specific groups or coworkers to share with so the right people are included in the conversation.
Want to use the Share Button on your own sites? We’ve made the code available on the Yammer Developer Center, so you can easily embed the Yammer Share Button within your own sites for simple Yammer sharing. For developers, the Share Button is our most lightweight tool yet, requiring no developer application registration so users can share quickly and easily.
Source: Yammer Blog