What do you think is the best use of social media?

I have been facebooking for a while now.   I started to keep track of my kids as they left home.  In 2008 I ran for House of Representatives and I started using it a lot for politics.  Later I started using it for real estate.  

I have a facebook page dedicated to real estate but I use my personal one.   I use it for everything.   I remind people that I sell houses.  I work my politics a little.  I keep track and post about my family and friend.  

Now this could backfire.  Someone could realize I am a Democrat and not use me....   I ususally don't friend a client until near closing.   I warn them that I post liberal comments.

I am a collage of everything I do.  I would think that just doing real estate on facebook would be really boring to the reader.  

As someone who ran for office I am careful to post only those things I am willing for everyone to see.   Even with that I think that if you are my facebook friend you will realize who I am and what I do.  I just don't want my friends to not realize I am a Realtor.   

So my question to you is what do you think is the best use of social media?