I have seen such effect before on Apple website but this one really cool: http://qindex.de/site/category/all/ . So what's happening here if you click on above link and let the page load in background, while you open up another tab and come back on this tab afterwards, the page will show some cool gallery effect and put contents in place.

I'm guessing this has been done by jquery focus method. But I want to know more what this effect called so that I can google and implement on my site.