I read/was told that it was a good idea to order your HTML to show the most important content first. So, on many sites I had put my global navigation div, for instance, below my main content div. Does this still apply? And does wise use of HTML 5 mean this is no longer necessary (eg use of "nav" section tag to indicate this section is about navigation). In the same vein, how does Google know that my sidebar nav is my sidebar nav (which your site seems to say is probably given less weight than top nav), and how does it know my topnav is my top nav? Maybe a daft question, but when someone asked me yesterday I realised I didn't know! (Phew - at last I have asked a short question!).