Uses a fake cursor to get the user to click on a Facebook 'Like' button. Could probably be used more deviously - perhaps cursor:none isn't a great idea.
Might take a couple of clicks to work. Also on OSX Chrome requires the cursor to leave the window and re-enter.
How does it work?
Hide the normal cursor, create a 'fake' cursor with an offset from the real one. Made slightly complicated because the Like button is in an iFrame - usually the 'fake' cursor would stop moving while the real cursor is over the iFrame. Solved by cycling show/hide a transparent DIV over the top of the iFrame.
Update: Demo now requiring an extra 'confirmation' step. It seems that FB starts requiring a confirmation of the like after a while - perhaps when a ratio of 'Likes' vs 'Un-Likes' is hit. This has been hit much sooner on the demo than on an 'evil' site since everyone has been alerted to the trick and thus knows to 'unlike'! Statement from Facebook developer here.