Even with emoticons, the waters can be murky. I've been recently told by someone that my habitual :P is being interpreted (by one person at least) as me sticking out my tongue in mockery, when I do it to show I'm being silly.
I use the lower-case P to stick out my tongue in mockery (in a typical serif font, it looks more like it's smiling than an upper-case P) and the upper-case P to stick out my tongue in sickness/exasparation/disgust/silliness.
Heh, so I'm not just being paranoid. I often thought it was someone muttering out of the side of their mouth in disgust more than a tongue sticking out though.
I use the lower-case P to stick out my tongue in mockery (in a typical serif font, it looks more like it's smiling than an upper-case P) and the upper-case P to stick out my tongue in sickness/exasparation/disgust/silliness.