Hello, I am currently in the process of designing and wondering how do some sites make their navigation to follow along as the user scroll down the page and restores back to its original position (right below the header)? Here is a rough sketch on what I meant, notice the navigation sticks to the top when the user scroll down, and when the page is scroll back up, the navigation will go back to its original position. I've seen some site do this, one of them that I can recall is Apple Online Store (Notice how the Summary and Spec panel moves). I've seen other sites do the same effect but can't recall the address or what it's called. Sorry that I can't give further information. Thanks in advance.