One of the interestingly constant things about males worldwide is that they tend to prefer women who are a couple of years younger than them. There are two explanations for this: the "why?" and the "why not?". I'll take the latter first.
When mankind's ancestors moved down from the trees and onto the plains, their social structure changed rather dramatically. Originally we probably lived in chimplike tribes, with complete promiscuity being the rule. Out on the plains, a monogamous arrangement proved more appropriate. If you want more detail, I recommend the book "Genome" by Matt Ridley.
One of the side-effects of this was that men developed a propensity to choose younger mates where possible, as this would increase the overall breeding lifespan of the relationship and hence the number of kids they could have. Obviously none of this was conscious - propensities for "marrying" older women were just selected against. That's our "why not?" answer.*
The "why?" answer is in many ways more interesting. In most men, as best I can tell, the propensity to chase women a few years younger than oneself manifests itself as a dominance issue of sorts. To my understanding, men have developed the tendency to believe that younger women will be willing to take a more submissive role in the relationship, thus providing their boyfriend/husband/whatever with a much-desired ego-stroking.
To be fair, this belief actually has a small dose of truth to it in our younger years, so it's not that surprising that men should take some time to shake the habit. But in general, although in some cases women will be flattered by the attention of an older male, a dominant girl will be dominant no matter what age her other half is. When men daydream about having some pretty young thing gaze adoringly up at them, they fool themselves. In reality, they're more likely to be set to work putting up shelves and mowing the lawn.**
One common adage in geek culture is: never attempt a technological solution to a social problem. Men appear to be making a similar sort of mistake - attempting to compensate for concerns about their social status by applying the fantastical magic bullet that is this hypothetical submissive younger woman.
In reality there is no magic bullet, and I suspect that part of growing up is realising that. The only solution for men is to meet the challenge head-on. Wish us luck.
* It's also related to one possible cause for human intelligence, but that's a different issue entirely.
** Yes, this is horribly stereotyped. I'm trying to write catchy prose here, not the frickin' manifesto of the Women's Freedom League.