A few ideas to consider...

A. Reminisce that point in your life again, and provide an update to "where are they now."
B. Write another revealing story.
C. Make a short documentary-video, youtube style, and post it.
D. Ask others to write something about you, and post those on November 1.
E. Contact the gal. Talk to her at length about the real story, and write to what she has to say now about it.
F. Explain your thoughts and feelings toward your blog then and now, and how it has changed - what you like, dislike, etc.
G. Don't wear pants for the day.
H. Finish your 2006 NaNo novel.
I. Write a commercial-like jingle about your blogsite, play it on your keyboard (sing it too!), and post it all as a post.
J. Interview friends, colleagues, and strangers, about your blog - treat it as though you are dead and gone, and have them discuss their feelings regarding the remaining art which is Brian Moon.
K. Build a small version of the moon out of Legos, paper mache~, or carved soap, and post your results.
L. Do a lunar photo-montage, and showcase it on the side of a building - at night. Record the event on video and post it.
M. Get rip-roarin' drunk.
N. Treat everyone as they are merely the paparazzi, trying to get a snap-shot of you for their celebrity-sighting blogsites.
O. Do everything the opposite of what you normally would do for a day, and write about the results.
P. Kiss four different strangers on the mouth. Tell them you've got to do it because I dared you. (I dare you!) And take a picture of you and the individual who you kissed - no pets.
Q. Write about all things related to the number four. Keep it short.
R. Write about all the most significant days in your life. Provide all sordid details.
S. Wear pants. And a tie. But that's all!
T. Throw a party. Invite all those you have written about within your blog.
U. Get your photo taken with every local (current) celebrity and post how you got the photo, and what they think of your blogsite turning four.
V. Do four things on your 43-List.
W. Ask for the phone number of everyone you meet, on November 1. Call only those who have a four in their number and leave a polite message.
X. Take a poll. Ask only four questions, related to all things four. Post the responses.
Y. Run for four hours. Then go and drink four beers.
Z. Write an anniversary post without using numbers, while still mentioning my name four times.

I hope this helps!