The article says that the researchers claim this is the first documented tool use in octopi, but that is completely wrong. I mean, we have a video on here already documenting the same behavior.
http://www.poetv.com/video.php?vid=63191
My dad has seen this too, while diving in the Caribbean. He says that it was delightful: an octopus carrying two shells like suitcases, and setting up its house in a few seconds whenever it stopped to rest.
Who is the cutest widdle invertebrate with an extra large brain. You are! You made that house all by yourself, didn't you? Do you want a hug oh look at your suction cups mmmpth mmph mmm mmm mmmph mmmpth.