I never thought of this before, but the One Ring was forged to fit men, not Hobbits, right? In that case, does it resize itself for whomever is possessing it? Because Bilbo and Frodo actually wear the ring, but the Rings of Power were forged by elves for Sauron - three for elves, seven for dwarves, nine for men - and the One Ring was forged by Sauron himself, who was a Maia, roughly the same size of a man. How does the ring fit Hobbits then?
Sauron was significantly bigger than a man, at the very beginning of the book Isildur describes the one ring shrinking down to fit his hand. You can even see this happen in the movie.
