>Thought it might be an interesting discussion thread...
Indeed. My favorite is a third printing of LAST CALL, where Tim
Powers had written in the "1 2" on the number line, and wrote
"honorary first edition".
I once left a book at a store for James Blaylock to sign, and I
wrote him a note telling him how much I liked his work. He inscribed
the book "Mike, thanks for writing this", which makes it look like I
had ghost-written the book for him.
I had a friend in London get an Iain Banks book signed. He got it
signed at a party, and apparently Mr. Banks was a bit inebriated,
because he wrote some weird stuff, and then had a few of his friends
sign it as well.
Finally, I have a number of books and proofs where the author has
written variations of "do you really think this'll become valuable
some day?", most of which have.