As far as I know, most of the girls I know aren't actually bi, they're just open to the idea of being with a woman in some form or another. I've heard the term "heteroflexible" used... and that's how I think of myself. I mean, I've never actually sexually been with a woman, but as that's the case, I don't know if I'd like it or not. There are some women I am attracted to, so I don't think I'd hate it.
But, claiming to be bi, or kissing other girls and such, is supposedly a great way to get a guy's attention. I think it's retarded, because then the girl doesn't matter... But whatever.