Justin Bieber vs. Miley Cyrus: It's a Mustache-Off!(Watch)

It's totally on between Justin Bieber and Miley Cyrus.In order to promote her appearance on Saturday Night Live this weekend, the latter was a guest on Late Night with Jimmy Fallon yesterday.She talked to the host about a number of topics, eventually settling on her obsession with... mustaches?!"I have a diamond mustache with me at all times," she said. "I collect all kind of things with