When I remember to do it, I usually check out the "pictures of the week" on msnbc.com - http://www.msnbc.msn.com/id/4999736/

I try to remember to check out the credits to see who shot the image and what agency is represented.  There are always a lot of AP, Reuters and Getty images.  What I find interesting is that MSNBC is a partnership between NBC and Microsoft.  Bill Gates owns Corbis or so I thought.  If that's the case, why don't I ever see Corbis images on this weekly feature?