888

Triple Eight is 24, *tut... tut... tut... * (from the show you know :p)

8 is the number of Chaos, the eight pointed star of the Discordian Chaos Magicians - I wonder if anything chaotic will happen at the Olympics?
8 is the number of Control - think handcuffs, could that chaotic thingy be used to impose more control on us?
Yeah I was confused about 8 resonating chaos and order both too, so this made sense: 8 is the number of the balance and of the cosmic order, according to the Egyptians. Teehee.
In Babylon, in Egypt and in Arabia, it was the number of the duplication devoted to the sun, from where the solar disc is decorated of a cross with eight arms.
8 symbolizes infinity when on its side, like after lunch in the couch.
8 is the number of Luck - Especially in China (because it sounds like the word "prosper" or "wealth"). Also in China, '8' is used in chat speak as a term for parting. This is due to the closeness in pronunciation of '8' (bā) and the English word 'bye'. (888 = N Sync's bye bye bye? :p)
8 is the number of perfection, symbol of Cosmic Christ and in China expresses the totality of the universe.
8 is a Fibonacci nr, being 3+5, the next nr in the series is 13 (5+8)
8th astrological sign of the Zodiac is Scorpio
8 Circuits of Consciousness model, the heuristic theory of conscious evolution by Timothy Leary and popularised by Robert Anton Wilson and Antero Alli.
Life Path 8 is the Path of the Warrior.
According to Michael from Hidden Agendas, 8 symbolizes material satisfaction.
In many countries, an Octagonal STOP sign is used. Even the hippies use it.
"The 'Freedom' tower" will be an Octagonal design.
added, thanks to Aferrismoon for posting this in the comments: "888 x 2 = 1776 (founding year of Bavarian Illuminati. 1776, or MDCCLXXVI, is the number shown at the bottom of the pyramid on the American dollar bill, and on the tablet held by the Statue of Liberty), obviously a good-opener. This'll be the height of the Freedom Tower in feet, which = 541. something metres, which by Gematria = YShRAL [ Israel]"
The Pythagoreans have made the number 8 the symbol of the love and the friendship, the prudence and the thinking and they have called it the Great "Tetrachtys".
In Stargate SG-1 and Stargate Atlantis, dialing an 8-chevron address will open a wormhole to another galaxy. In Battlestar Galactica, the nr 8 model is played by Grace Parks. The character Sharon Valeri clones with the nicknames Boomer and Athena.
In Terry Pratchett's Discworld series, eight is a holy number and is considered taboo. Eight is not safe to be said by wizards on the Discworld and is the number of Bel-Shamharoth. Also, there are eight days in a Disc week and eight colours in a Disc spectrum, the eighth one being Octarine.
In Colombia and Venezuela, "volverse un ocho" (meaning to tie oneself in a figure 8) refers to getting in trouble or contradicting one's self.
8 is ACHT in Dutch and German, ACHTUNG means WARNING or PAY ATTENTION in German
8 is HUIT in French, Huit sounds like Oui, Yes! Also sounds a bit like WITH, WIT in English. Wit translates to 'white' in Dutch.
8 is Hachi in Japanese, bless you.
w8 is wait, in dutch too: w8 is w+acht = wacht which means wait. Other words like that (which don't work in dutch) are h8, gr8, appreci8, congratul8ions, sk8
888 is also the Lions Gate. A supposed DNA Activation meditation Gateway, I don't know enough about this stuff yet to judge or talk about it really, it's on the list to investigate. Here's a site about it, apparently it has something to do with the rising of Sirius.
I 888 (ate, ate, ate) cause I was hungry.
88 is the abbreviated terminology used by the Aryan Brotherhood for the Nazi salute, "Heil Hitler" — "H" being the eighth letter of the alphabet, twice.
Eight is symbolic for lesbian sexual relations. YEAH!
Check out a li'l more at Pseudoccult about it, with a hilarious realisation that the Olympic logo looks like a dead dude in his own pool of blood, ouch.

You can see I don't take symbolism too seriously as you can interpret in so many ways, but it's so fascinating. I'm sure I forgot loads of interesting stuff, please share anything interesting in the comments.

added: got sent this via myspace, thanks Thom
From a book on numbers:
8 is 2x2x2, and as such is the first cubic number after 1. As the vertices of a cube or faces of its dual, the octahedron, eight is complete. At the molecular level this is displayed by atoms, which long to have a full octave of eight electrons in their outermost shell. A sulfer atom has six electrons in its outermost shell, so eight atoms get together to share electrons, forming an octagonal sulfer ring.
Within architecture the octagon often signifies the transition between heaven and earth, as a bridge between the square and the circle. A spherical dome often surmounts a cubic structure by way of a beautiful octagonal vault.

Eight is particularly revered in the religion and mythology of the orient. The ancient Chinese oracle, the I-Ching, is based on combinations of eight trigrams, each the result of a twofold choice made three times. Depicted opposite is the "Former heaven Sequence", said to represent the ideal pattern of trans-formations in the cosmos. Note how each trigram is the complement of it's opposite.
In religious symbolism, the eight step is often associated with spiritual evolution or salvation. This may result from the fact that in a seven-tone scale the eighth note is the octave, twice the pitch of the first note, and so signals the movement to a new level.
In the modern world, computers think in delightful units called "bytes," each made of eight binary "bits."
All spiders have eight legs and all octopi have eight tentacles.

Also:
eight taoist immortals.
eight limbs of yoga
eightfold path of buddhism

Update: Opening Ceremony Remarks
I didn't see the very beginning and tuned out a lot. 100 million US$ spent on the opening and closing ceremonies by Beijing officials, holy crap.

The first thing I see is soldiers freaking goose stepping lol. But then they showed paper making and calligraphy. A huge scroll folds open in the arena, I've been meaning to post on the view of multiple reality tunnels that life seems to be a meta-narrative, so I'll get back to that. As the scroll opens, life begins (Beijings? ;p). Ice Sk8ers skate and write on the paper, we write the story. In the backdrop of the filming of the scroll, we see a yellow triangle thingy with an eye in it, naturally. Then we see mountains scribbled, with a top one looking like another pyramid with an eye, in case you missed the first one :p and the sun at the right side of it above the mountains. Then the 3000 disciples of Confucius come out.
After not paying attention for 20 minutes, I mean damn these things are boring :p, white chinese runners converge in a spiral (stargate) and form a bird with a hole in its center where video is played in a series of frames. Then suddenly I hear the commentator say "the galactic center gets poured over the earth" as we see glitter thingies going down, based on the work of a Chinese artist. And the last notable thing I saw was A tai chi performance by 2008 people. I'm sure others will note some more peculiarities. Like Secret Sun's post: 17 Days in Beijing and check out another Olympic post here from Ellis Taylor.

added: how many times have you heard "one world, one dream" today? :p In the news here they mentioned it before going to the Russia-Georgia-Ossetia conflict. Interesting flag Georgia has, Russia is interfering to stop the Templar rush. In some hopeful news the three professions the Belgians trust the least of all are: politicians (only 1 in 5 trust 'em, talk about approval rating), CEO's and journalists lol! All is right with the world. Some other interesting headlines...
US government points to dead scientist as 'lone anthrax attacker' (lol, no shit!)
Nader chosen as the presidential nominee of the Peace and Freedom Party
Pakistan civilian government unites in a coalition to impeach President Pervez Musharraf
Maine resident arrested in Florida for death threats to Bush, Obama