You may remember
this, which I will summarize briefly here:
First, Ringo Starr
had this to say.
So I sent him a Sharpie letter:

(for more Sharpie letters, see
here,
here, and
here)
In an envelope with a microcentrifuge tube opener, a tool of the scientific trade:

Which included a blown up, badly pixelated "RINGO!" poster image which I created myself and a self-addressed, stamped envelope. This was sent out October 16, 2008.
Yesterday I got home, and in the mailbox found this:

It took me a bit to remember when the hell I'd SASEd, as I don't often apply for promotional materials. I opened it up, and this was inside:

My first ever Sharpie response!!! Please note the fine signature on my horribly pixelated, creased-to-the-point-of-removing-ink RINGO! picture. If it looks OK here, click on the image to get it full-sized(ish) and you'll see how bad the image is. Too much fun.