Single page websites bookmarking, history & back button

It has come time for me to design a new online portfolio. My previous design was using actionscript but and it is time for me to move on to javascript to access devices such as the iphone & ipad. By far the finest javascript site I have seen is imagemechanics.com.au. Most websites a I have seen manage to change the address bar and record history using some sort of hash tags but unsuccessfully utilise the back button. Is there any direction you can send me in in order to create a single page website that still manages to utilise the browser functions and history?

What I find most surprising about the site above is it recognises the use of the the back button or the user-side change of the web address and seamlessly animates to suit. This is what I would like to achieve in particular.

Thanks!