If you are involved in any of the Social Media avenues...(such as Facebook, Twitter or maintaining your own web site or blog) you want to get the most exposure you can out of your efforts.  Identify your viewing market and don't forget to put a face or faces out there so folks can relate to an actual human being. 

Many time we work on "Branding" our business or organization - and that is a great thing!  But we forget the human factor. 

Perhaps you're representing an organization...that could be ecological, or a non-profit working with children, find the face(s) that represent your best.  Get a release form unless you know that you know that you know the person will never sue you (for example - yourself)!  Then place the image(s) when appropriate in articles, front page of your web...or create an event on Facebook within your Fan page.  From what I hear, Twitter will be rolling out the ability to include image within the next few weeks.

So go ahead, get some "Face" time.