Just about each of my posts are nostalgic or something like that. Why? Because I pick up things from people, that's why!
@_@ & U_U & <_< & >_> = I picked these up from Coruscate/Kougetsu.
^o^ & *_* & ^_^ & ^.^ = I'm not sure about the last one, but I'm pretty sure that I got the first three from Samiko. Actually, I think I got ^.^ from Kimiko.
<.< & >.> = I believe I picked this up from Jayme, way back when I was actually active in IRC.
:3 & X3 = I got these from Musashi.
XD = Hmmmm... A lot of people made this face when I did a certain something... But the earliest and most likely source might have been Lioconvoy.
X_X = Wait... I might have gotten this one from Samiko as well, although I have encountered this many times in response, if not XD, to things that I do.
;p = I'm not sure... At all... <.<;
:O = I picked this up not too long ago, from Xia/X. Although I use a big O so I don't have to disable smilies so it doesn't make a smilie with a small o.
~.^ = I can't really say... But I know the source did it like this, ~_^, instead of how I do it. Might have been Samiko... But I'm unsure.
~.~ = Another I'm not sure about. From someone in IRC, most likely.
-_- = Also likely from someone in IRC.
._. = I may have gotten this from Musashi, but I'm not sure.
^-^ = I rarely use this now, but I think I got it from Samiko.
>:O = Sometimes I use this, and I think I got it from Musashi.
>.< = I probably got this from IRC... From who knows who. ^_^;
^^ = Whenever I use this, I either think of Kerina or Angelic Celestia.
O.o = I think I got this from Jayme... From IRC for certain, though.
And that's about all that my brain can poo out.