Random element position within box (Multiple Photos)

Tried searching but didn't find an answer to my question.

I wonder if there's a plugin (Javascript/jQuery) to position elements randomly within a box. Overlapping each other.

I've seen similar features in lots of websites. Not necessarily with the elements overlapping each other, but with random position. Example: http://ift.tt/1ESkiwd

Here's an illustration of what i'm looking for: http://ift.tt/1IGPAxs

What i wonder is if there's a existing plugin that does this. Like Masonry.

All help appreciated!

Thanks,

F