Personally, I'm a fan of typography. I love the fact that with prudent selection and placement of types, it can really change the impression perceived by viewers. Bearing that in mind, I would refrain from placing signature on a photo as it kind of beautifies the photo and suppresses the original feel that it would otherwise radiate. Nevertheless, i understand that to the majority, it will "protect" the photos from misuse.
What's your take on placing signatures on photos?