I've heard this rumor around but have you guys ever done it or heard about it? If you fill a 1 gallon jug with pop tops some liquor stores will give you a free keg.
...and if you forward an email to all your friends, Bill Gates is gonna give you a crap-load of money! And your wish will come true!
BTW, I'm a wealthy deposed ruler of Nigeria and I have $650 million dollars in international accounts, if you help me get it I'll give you some of it...