notmeh1 PMed me with this one, but asked me to dedicate it to wearetheworld1998 so I will :)
Michael used to put cologne on his letters to Lisa Marie Presley sometimes.
There's quite a few pictures on the Internet of letters (from MJ to LMP) with a box and an arrow saying "smell here". I found one of them, which is in the photo section. If it doesn't show, just search "Michael Jackson letters to Lisa Marie" on Google Images.