Why is it that it's more acceptable for public displays of male semi-nudity (i.e. topless) than for females? You see it everywhere: ads for fragrances, at the beach, on a hot day, on TV, in movies, etc. Men can just walk around with their t-shirts off, bare chested, and nobody cares; if a woman did the same, parents would be averting their children's eyes, media companies would be barraged with complaints and she'd be made to put clothes on or, laws permitting, even arrested (Can the police do that? It sounds plausible.).
Obviously, there are plenty of nude woman in more adult films and on Page 3 of the Sun, but male toplessness is a lot more common and a lot less frowned upon - why is that? When it comes to below-the-belt nudity, it's a different story; fully naked males and females are both a bit "taboo", if you know what I mean. What's so different about the other half?
EDIT: Another point I'd like to make - if you see topless women in magazines (like candid celebrity photos or whatever), only the nipples will be censored, usually with little stars. Men have nipples too, right? So it's obviously not the fleshy, breast tissue that's the "problem", it's the nipples - this makes less sense because the breast tissue is the only thing different between men's and women's chests (please correct me if I'm wrong).