Make element change place on screen resize?

Hi, im doing a responsive website and i want to try out something different. When i make a responsive website i usually make all the element inside the page resize depending on screen size. But now i want the
elements to stay the same size, but drop down to less columns/change places.

Here is an example of what i mean: http://etchapps.com/

How would i do this? Only make the container responsive and the inner elements floated left?

thanks in advance.