"O_O" is usually used after and between perverted statements, as well as after surprising or shocking statements. Though it may hard to believe, if one is exposed to "O_O," it is usually very hard not to use the emoticon again due to its attractiveness.
<Potter> Tell me when you've added one for Lanta Jones. O_O
<Potter> sorry O_O
<Potter> DON'T HATE ME. I'M ONLY 11.
<Potter> jk O_O
<Potter> found it O_O
. or - or _ mouth
* you also can add the ; as in sweat drops in expressions like: Surprized, weirded out, scared, or Thats emberessing..
<(-"-)> - Kirby
'x' - Kitty
(^.^) - Bunny
('o' ) - Bird
( '_o' ) - Koala bear thing..
joo /\/00b!!!1 1!1!1!!1im sooo awsum!!111!11one!!! !11!!!!eleven!!! "11!"211! LOLOOLOLOLOLOLOLOLOLOL LOLOLLOLOLLOLIPOP