It's a smiley face with a nose. The ':' = eyes, the '0' = the nose, and the ')' equals the mouth. The mouth symbol can be replaced with other symbols such as:
- R (Thorn in tongue)
- J (Smirk)
- ( (Frown)
- | (Blank)
- \ (Skeptical)
- / (Confused/Concerned)
-
[
(Tight Frown)
- ] (Tight Smile)
- O (Surprised)
- D (Big Smile)
- P (Tongue out)
- B (Big teeth)
- And so forth... But these are the ones I use most frequently. :0)