Dynamic gallery thumbnails (example included)

Hi, I have a photography website and I would like to display my gallery thumbnails in a dynamic fit… I’m not sure what the actual name for this is, that’s the only way I can think to describe it.

My gallery is here: http://www.danpowerphotography.com.au/gallery, as you see it is laid out in a rigid and boring table. I would like it to display like this: http://www.peteradamsphoto.com

You can see on the second site how the images seem randomly placed yet fit perfectly together and it is a must neater look. I see this style on many websites, is there a plugin for wordpress that will give me this look?

I am using the latest wordpress and WooCommerce for my gallery/store.

Thanks very much for your help