Add "Pin" Button to Make Posts Stay Popped Out

On my website, I want added a button called "Pin" in box where you uploaded something. The website has it so when you hover over a post, it pops out using simple CSS3 transitions, when you hover off it goes back to normal. I want when you click on the new "Pin" button it will stay popped out no matter if you hover off or not. This is to stay popped out no matter if you log out, reload page or whatever, until you click the button that will now say "Unpin". This is all that's required.