As extracted from The Straight Dope.. full article here
"Bottom line: the number 666 has become associated with Satan in western culture, and appears that way in literature and film. Often this is explicit, in films like The Omen, but sometimes it's more subtle. According to Wikipedia:
In Clockwork Orange, two police officers are numbers 665 and 667.
In Pulp Fiction, the briefcase is opened by the code 666.
The opening of Andrew Lloyd Weber's musical Phantom of the Opera is an auction, where lot 666 is the famous chandelier.
And, of course, there was that joke list making the e-mail rounds a while back that included:
666 = number of the beast
665 = older brother of the beast
660 = approximate number of the beast
66600 = zip code of the beast
1/666 = common denominator of the beast
665.95 = retail price of the beast
and so forth.
SDSTAFF TUBADIVA ADDS
I am happy to tell you there's more:
660 = Approximate number of the Beast
DCLXVI = Roman numeral of the Beast
666.0000 = Number of the High Precision Beast
0.666 = Number of the Millibeast
/ 666 = Beast Common Denominator
(-666) ^ (1/2) = Imaginary number of the Beast
6.66 e3 = Floating point Beast
1010011010 = Binary of the Beast
6, uh . . . what was that number again? = Number of the Blonde Beast
1-666 = Area code of the Beast
00666 = Zip code of the Beast
666mph = The speed limit of the Beast
$665.95 = Retail price of the Beast
$699.25 = Price of the Beast plus 5% state sales tax
$769.95 = Price of the Beast with all accessories and replacement soul
$656.66 = Walmart price of the Beast
$646.66 = Next week's Walmart price of the Beast
Phillips 666 = Gasoline of the Beast
Route 666 = Way of the Beast
666 F = Oven temperature for roast Beast
666k = Retirement plan of the Beast
666 mg = Recommended Minimum Daily Requirement of Beast
6.66 % = 5 year CD interest rate at First Beast of Hell National Bank, $666 minimum deposit.
$666/hr = Beast's lawyer's billing rate
Lotus 6-6-6 = Spreadsheet of the Beast
Word 6.66 = Word Processor of the Beast
i66686 = CPU of the Beast
665.9997856 = The Number of the Beast on a Pentium
666i = BMW of the Beast
DSM-666 (revised) = Diagnostic and Statistical Manual of the Beast
1232 Octal, Apt. 29A = Beast's hexed address
668 = Next-door neighbor of the Beast
333 = The semi-Christ "
I love Straight Dope.