You might think, as I did, that emoticons are universal, but turns out if you're tweeting someone in Asia, you need a translator for emoticons, too. Want to add a smiley to the end of your message to Beijing? You should know that :) is (^_^) over there. To Asian speakers, the meaning of emoticons is derived from the eyes, while Western emoticons more often use the mouth to express meaning. A good illustration of this is the sadface. Look at our :( versus their T_T which is meant to suggest tears streaming down.
Western emoticons read left to right mirroring the way we read romance languages. But in Asia, emoticons read straight-on like pictograms, reflecting the graphic nature of character-based languages. Is it because Asian readers are more accustomed to graphic characters, or because they're more in touch with their feelings, that their emoticon glossary is more extensive than ours is. They've even got an icon for the pleasure of smoking.
(-.-)y- cigarette break
(v_v) silent resignation
(o_O) confused, surprised, disturbed
d-_-b listening to music
fO_o scratching head
\(^o^)/ happiness or wow!
(o)_(o) tired; sometimes used to mean crazed
(/_\) profound dismay
(H_H) pervert (from Japanese "hentai")
x.x Dead (in which case, how are you messaging?)
($_$) or (¥_¥) or (₩_₩) money eyes; thinking about money
And my two favorites:
(x(x_(X_x(O_o)x_x)_X)x) Alive among zombies
(-(-_(-_-(O_o)-_-)_-)-) Waking up in the subway
Joker adds a few of his own creation:
Bull fighter or horn dog. you pick
Wishydig observes that Western emoticons don't read left to right any more than Asian emoticons read top to bottom. Western emoticons are turned on their side, but they are still just as image based. He sends a handy link to the world's most complete compendium of smiley face options, perfect for any occasion, including when you need to convey that "user is a midget" or "user is the Pope."
More emoticon translations here and here and here