We heard that this was on it's way and now it's been confirmed - Ben & Jerry's Free Cone Day on April 14th!* There's no catch, all you have to do is visit a Ben & Jerry's Scoop Shop between 12pm and 8pm on 14th April and you will be given a free ice cream cone.
Not all the scoop shops are participating, but you can find out if the one near you is by using the Scoop Shop Locator* on the Ben & Jerry's website, and ticking the box that says "Participate Free Cone Day".
Most of them seen to be located inside Odeon Cinemas, and using my usual sources of info I can tell you that it's a one scoop sugar cone that you get, you can choose which flavour ice cream you want, and it's limited to one per person. You may be asked if you wish to donate to charity at some sites, but you don't have to.
Also... some people just join the back of the queue again once they've eaten their ice cream, and get another one. Or two. Or more!
So check where you can get your Free Ben & Jerry's Ice Cream Cone and get the date in your diary!