Haha, yeah I remember that. I thought my iPhone was glitching up for a second before I checked the date. You must have enjoyed that day. :)
Yeah, I knew about "xD" (it's hard not to given how popular it is these days) but I just didn't understand the semicolon. And yeah, I use that one ("that" meaning "^^;" ) quite a bit but at least that one makes sense. With "xD;" the sweatdrop is coming off the chin and falling sideways. :\
Personally, I think all these complex smilies are just useless. Similes are supposed to be used to compensate for the lack of inflexion and body language over the Internet but a lot of them just seem excessive.