I’m interested in seeing how you could run a WordPress Query to accomplish a layout such as this when you grab posts:
http://planetpropaganda.com/#!/blog

As you can see the boxes have varying heights (mostly because of different excerpt lengths).
What they’ve done looks great, however since the boxes are absolutely positioned, I don’t believe it works well with a responsive layout.
Anyone have a clue?
This layout is called Dynamic Grid Layout which (maybe) firstly implemented by Pinterest. People always call id “Pinterest-like Grid Layout”.
I have a link which give a nice introduction about “Pinterest-like Grid Layout” which may help you understand it.
And Introduction to Pinterest-Like Dynamic Grid Layout
and if you use jQuery, you may consider to look at a list which this link has. There are 5 jQuery plugins listed there.
5 jQuery Plugins to Produce Pinterest Like Dynamic Grid Layout
If you want to get other resources about how to create that layout, start googling “Pinterest-like Grid Layout”, you’ll find your way.