I actually came across this article several weeks ago, but just never came around to blogging about it. Eyetrack III has released their results from their latest testings and the results are pretty interesting, but not exactly surprising.
In a nutshell, this survey tracked users and the movement of their eyes when viewing a web page. Here is a diagram of how most users tended to first scan a web page:
They have some interesting charts and information on their site that you may want to take into consideration when doing your next layout. I do have to add that I think user's eye movement is probably conditioned to this pattern, more so than it being an instinctual behavior. Since so many sites use the same basic pattern/layout. Regards, it's still interesting to know what portions of the screen users tend to focus on.