What's 666?
Bible prophecy says that in the future a dictator will head up a global government. He forces everyone to take a 'mark' without which they are able to buy or sell. This http://www.countdown.org/mark_of_the_beast.htm seems to be a chip implant which will work with some form of http://www.countdown.org/end/mark_of_the_beast_02.htm#mar_future_of_money. The Bible says that 666 has something to do with that mark. So what's 666? Speculation abounds! God loves a mystery and this is a big one. Some folks say it's the addition of a person's name (in Hebrew, ASCII, or Greek etc...). The Pope, Bill Gates and Clinton have been candidates, to name a few. Others say 666 is the web (WWW), or a barcode system.
Here's the actual verse from the Bible has to say about it:
And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.
Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six.
(Revelations 13:17-18)
So basically it says, "If you're smart, when the time comes here's an additional clue to recognize it: It has something to do with 666."
One thing that we do know for sure is that all throughout the Bible the number 6 has been used to indicate man. The number 7 represents God and 6 is just beneath him, a little lower.