"Ex Libris is a Latin phrase, meaning literally, "from the books". It is often used to indicate ownership of a book, as in "from the books of..." or from the library of..."
I love books, and even in this digital age, with iThis and E-Ink that, I still want to read and own as many physical books as I can, or at least as many as my bookshelf will hold without collapsing under its own weight.
When I on occasion borrow one of my books to somesome, I have always so far written my name on the inside, as a gentle reminder of ownership (or maybe I'm just a distrusting bastard, who knows). However, this has always been a bit annoying to me, because years spent in front of a computer keyboard have not been kind to my handwriting.
My very own Ex Libris rubber stamp solves this, by providing me with an easy way to mark my books, without having to impose my terrible penmanship upon them.
Additionally, you know, it's like super cool.