The explosion of online dating sites, some of which are free and require no registration, has been a boon for psychologists studying the deception and mind games of the dating scene. Scientific American has an article on what they're finding-- nothing that will really surprise GNXP readers:

For men, the major areas of deception are educational level, income, height, age and marital status; at least 13 percent of online male suitors are thought to be married. For women, the major areas of deception are weight, physical appearance and age.
...
My research assistant Rachel Greenberg and I have examined the age issue by plotting a histogram of the ages of 1,000 men and 1,000 women selected at random from the national database of Match.com, arguably now the largest of the online matchmaking services. We speculated that from age 29 on--the point at which people in our culture tend to become sensitive about growing older--we might see some distinctive patterns in the distribution of ages. For men, a small spike appeared in the ­distribution at 32 and a large one at 36. The number of men calling themselves 36 was dramatically higher than the average frequency of men between the ages of 37 and 41.

For women, we found three clear age spikes at 29, 35 and 44. The difference between the number of women claming to be 29 and the average frequency of women claiming to be between ages 30 and 34 was nearly eight times larger than we would expect by chance. Apparently women at certain ages are reluctant to reveal those ages--and certain numerical ages are especially appealing, presumably because our culture attaches less stigma to those ages.
(via Matt)

That women find socioeconomic status attractive is unsurprising; in my experience, though, there are even more subtle things that affect interest levels. For example, telling someone I'm a "geneticist" always gets a better reaction than saying I'm a "biologist" (people who know me are laughing, because they know neither is technically true. Whatever). I've never really understood this-- does genetics sound more impressive than biology?