Hey, I'm no English major but somewhere along the way I think one of my teachers actually taught me something good.
Here is the way I learned it:
I am looking forward to...... to what? to meet you? that makes no sense at all.
I am looking forward to..... to what? to meeting you. Now that makes more sense.
I know nothing of gerunds, and participles totally bored me to tears in school, but this simple lesson made an impression.
P.S. I ran across this page while looking for an alternative to the old cliche - "looking forward to meeting you". someone on an earlier page suggested "I am looking forward to our meeting". I can't see who's suggestion that was while I'm typing this response, but thank you anyway for the simple alternative. :O}