I've got one. Haven't really tried it- it comes lightly glued to a card, and since it's TINY and easy to lose, I've been reluctant to remove it. The instructions do make it clear that it is not buoyant, that it floats by surface tension.<br><br>I'm sure it works under ideal conditions, but I'm skeptical in general. I can't see this working in the wind or rain, it seems useless if you don't have water, and it is so very tiny that I think you might have trouble not losing it in a pocket.<br><br>On the other hand, if you really NEED a compass, it's probably a lot better than nothing, and it's the only one I'm aware of that you can carry in a wallet. I wish it weren't.<br><br>It seems to me that it might be possible to do something with the magnetic strip area cut from an old credit card... maybe cut into an arrow shape, remagnetized, and a short thread fastened at the balance point? It would be easily carryable in a wallet, and at least it woudln't require water. Just a thought. If it worked it might even make a Scout project, for those looking for such.