There's a great article at Science and Spirit speculating about the release of a male contraceptive pill (maybe by the year 2010). It turns out to be something of a marketing challenge, even marketed to men in committed relationships, because of ideas about loss of virility. It's most successfully addressed by framing it as the caring, responsible thing to do.
What's even more interesting is the sort of game-theory sociology which emerges: if a man who's on the pill goes off the pill, there still won't be a pregnancy if the woman is on the pill. Yeah, but the converse is also true, right? And anyway if people know each other well enough to be having sex on a regular basis, doesn't it seem likely that they'd try to agree on their reproductive preferences?
Or is that just (wait for it) inconceivable?
Read the whole thing.