Signature - Adding html code?

I was forwarded a message from a friend that had a sig which (upon
inspection of the source) included a marquee tag that had a rather
interesting effect when the message was opened. My friend was asking
how this was done, and while I understand the code and how to use it
etc, I wasn't sure how to insert it into the sig (or the body, for that
matter) of an email. I can VIEW code on an inbound message easily
enough (which is how I found out what the code was), but I don't see an
intuitive way to ADD html tags like this to an outbound.

I don't know for a fact that it was done in Outlook (2003), I'm just
guessing, but I was wondering how this could be done.

Um, I should note that *I* don't want to do this, my friend does

TIA

elaine
charlottesville, va