I just performed a Google search for the words "Google Analytics" and noticed half way down the page that there was an image next to one of the results:
How can I achieve this? Having used Yoast's plugin I know how much of a genius he is!
Here's how he did it: http://yoast.com/highlighting-wordpress-authors-search/
According to this discussion on Google+ they only like real photos though, not cartoons.
Paul is right, this is accomplished via the new rel="author" markup offered by Google.
Joost has a great technical write up on the topic but I did want to clarify that you usually need a set of three links.
There is actually a streamlined way (with two links) but it seems to be less reliable at this stage, in part because the Rich Snippets Testing Tool had a bug that would produce a false negative.
For more details, including how long it may take from implementation to display, you can visit my own post on How To Implement Rel=Author.