Back in June of 2005, I bragged about how I spent a few hours to write Outlook VBA code that eliminates a few keystrokes. I had a request for that code a few days ago, so I decided to edit that post to add the code. This link will take you to the edited post.
I should point out that I no longer use that code. I had lost it when my work computer was upgraded, and I failed to back up the source in a reasonable location. Too lazy to re-invent the wheel, I deigned to add signatures the MS Outlook way, using Alt-I S M X Enter. Besides, after a security patch was applied, Outlook would force me to respond to a warning every time I ran that macro. And anyway, when adding the signature to replies, I would always have to move the signature from the very bottom of the message to the point just after the end of my response and before the quoted message. (I'm pretty sure I can fix that, actually.)
So the code you see in the edited post came from an hour-and-a-half session I spent to recreate the code -- a Saturday night pursuit of geeky leisure.