I think though if it was disable[able], and the smilies were sizable accordingly, it would be a great feature!
Or there were some sort of function to simply replace certain strings with images. That way, if a user didn't like the default smily images (if any) that were disted with mIRC, they could simply replace them to better suit the colour & font scheme of their script.
It would also allow users to add their own custom smilies to the script.