So I was idly toying with a Bic lighter on the table last night when I discovered that you can, if you're careful, balance it at a slight angle from being upright. There is a small lip on the bottom that allows this. It takes practice, but it can be done fairly quickly without much notice.

So how to turn it into a trick/bar bet/etc? Well, if it's leaning toward you a little bit, and you tap it (near the top) gently but firmly with your fingertip, it will start to tip over the other way, then rock back and fall toward you.

You can do this nearly every time, with it pre-set, bet someone they can't match your feat. You have it set up to fall backward (toward you), but when they set it up, it will be completely upright, and will fall over forward (almost every time).

Naturally, this is far from foolproof. I tried it several times, and it takes some precise "tapping" to get it to fall toward you, even if it is pre-set at its "special angle." I suppose you could cheat the first bet by tapping/flicking the bottom of the lighter, which would make its bottom end slide forward, naturally making its top fall toward you. But then, your friend could just repeat what you did.

Or, you could pre-place a few grains of salt under the opposite end to ensure that it is angled properly (ie in your favor). You hand the lighter over to your friend, they put it in a different spot, and can't repeat it.