You may already be familiar with eye tracking, a technology used to conduct marketing and usability tests for websites by examining the vision patterns of users as they view a page... but have you seen it in use? Etre, a company specializing in usability, offers an eye tracking service for clients, and features a video of what eye tracking looks like on-screen. Watching other people's eyeballs flick back and forth made me self-conscious about my eye movement for about five minutes...eugh. But I would be curious to see the results for some big-name sites, as well as for SEOmoz and our clients.