a professor of communications at Stanford University says that emoticons give people "the ability not to think as hard about the words they're using."
which I find a tad worrying. It's an admission that lots of us feel it's no longer necesary to bother to construct sentences that adequately convey our meaning. Why bother to write expressively if an emoticon can tell people you're happy or sad, or that you're really only joking?
that its an invention of the digital age, and as such was first used within living memory. Personally, I dont think that we will ever have a definitive answer to its originator, but I do think its quite interesting that such a simple thing has achieved virtually global recognition in such a relatively short period of time, circumventing language barriers in the process.