You can add a contact's Facebook, Twitter, LinkedIn, Flickr, YouTube, Google+, Pinterest or MySpace addresses to their contact records, in order that you might quickly access information that is currently relevant to them.
To add any of these addresses, go to their contact record. Then, click the Add option next to Social Media in their Contact Card:
You'll then see the below dialog:
If you then click the arrows in the box that by default says "Facebook," you can choose which Social Media channel address you'd like to add for the contact:
After choosing the channel, simply copy and paste or type in their relevant Social Media address, click Save Social Link and their address for that channel will then be saved in their Contact Card, providing you with one-click access to that Social Media address. After completion for all of the available channels, this particular Contact Card might look like the below: