2) On my last flight, I found a book of 4 500 mile upgrade certificats in the seat pocket (talk about lucky!) The only thing is that these aren't the regular certificates; they were bought by somebody (the $125 for 4 certificates deal). On the last page of the book, there is a reciept with the guy's name, and MP number. But the actual certificates themselves don't have his name on them (there is, however, some sort of number on them) So can I still use them? Or does the certificate have some sort of number on it that would indicate that only the person who bought them could use them?

Do the right thing, they can be returned and should be.