Does anyone know how Pinterest.com's layout works?

Question

On http://pinterest.com/ there are \'pins\' ie

s of varying height but they all seem to render very well with no \'gaps\' or line breaks to interrupt the flow. Is

Answer 1

Andrews answer is amazing! I was searching for a solution and finally got it... As Andrew wrote by positioning.. Here my JS snippet. Not perfect, but the right direction. Thanks Andrew!

var tilename = 6;

for (var i = 0; i < document.querySelectorAll('#tiles .t').length; i++) { 
    document.getElementsByClassName("t"+tilename)[0].style.top = document.getElementsByClassName("t"+(tilename-5))[0].offsetHeight + 10;
    tilename += 1;
}