What is Google Authorship markup?
Chances are if you use Google to search the internet then you have seen a result that shows a thumbnail photo of its author. Here is a couple visual examples of my Google+ profile linked to some content I produced to give you a better idea:
You can see from the examples how authorship markup effects the SERPs (search engine results pages). I want to point out that my photo of myself skating is bending the rules slightly in that Google requires the photo be a good face picture. I am working to get a better photo of my face in there but wanted to test the limits of what Google would allow and somehow the photo above passed the test.
Click here to read more information from Google on authorship.