To avoid graphical smilies, insert a space where the nose should be:
: )
Who needs noses! IMHO, this looks better than the usual ":)" anyway, since the default sans-serif font compresses the eyes too close to the mouth.

Disclaimer: Use at your own risk. Especially as the last time I used an authorized AIM client was several months ago with a client that had not been upgraded in at least as long. They might have caught on since then...