Social Networking is booming in last few years. For example, Facebook reaches 500 million users(as on July 2010) and Twitter has 190 million visitors per month. It's human tendency to know about others and share information with them. In any organization collaboration is key thing and it helps to improve operating efficiency.
SharePoint 2010 development team keeps all these in mind and bundled cool Social Networking features with SharePoint 2010.
Social Networking Features
- Ask Me About
- Activity Feed
- Tags & Notes
- Tag Cloud
- Improved Profile Page
- Global Picture Library
Each of them takes collaboration to next level.
Ask Me About
"Ask Me About" is great feature for employees to share the areas(Skills and Interest) where they have good knowledge. For example, In a Situation when a developer wants some help in a technology, he desperately needs expert advice. With this feature he can search and find people who are experts in that technology.
Activity Feed
"Activity feed" is like task log which has list of activities done by the user. Those who have access to it can watch and track. For eg. It's great to readers those follow technical authors for tech articles. The feeds list is fully customizable and realy useful.

Tags & Notes
Tags & Notes help users to create and manage page tags and small notes. Users can create tags of their own and add page reference to those tags(public/private) just like shortcuts. Users can see public tags of other users. Notes help to keep small text content and refer when required. It's possible to tag a Internet site/page link with SharePoint 2010. For this a SharePoint link available in Tags & Notes window that needs to be added in Browser's favourites. While browsing internet, just by clicking added favourites link the link can be added as a tag in SharePoint. It's really nice feature.
Tag Cloud
Tag cloud is based on user Tags and helpful for those who search certain terms. When a user search a term in tag cloud, he'll get all page links which mapped to the given tag.
Improved Profile Page
User Profile page in SharePoint 2010 is realy interesting and user can customize as required. Each item in the profile can be customizable in terms of security like to display only to me, to manager, to colleques, for everyone.
Global Picture Library
Now SharePoint 2010 manages global picture library like central repository for user profile pictures. SharePoint resizes the uploaded photos automatically as required and it can be even used by other applications.