What does it mean when a phone has integrated social networking?

[girlborofan]

Integrated social networking means that all the social network sites on the phone will work together. For example, you can update your Twitter feed and it will automatically add the same information to your Facebook status page at the same time.

To answer your other question - no you cannot use these services for free; you will need an internet/data account on the phone to use them.

The only way you can get Twitter, Skype, Windows Live Messenger and limited access to Facebook without paying for it; via a phone; is to buy a phone on the three network.