Nichole Trunfio

Pulling out works.... most of the time. In a paper published in the June issue of Conception magazine, researchers claimed that withdrawal was "almost as effective as the male condom" when it came to pregnancy prevention (a failure rate of 18 percent, vs. the 17 percent failure rate of condoms).

Sex smells. A man's sweat smells different when he's sexually aroused — and women can tell the difference between the smell of sexual sweat and the regular stuff, according to a study in The Journal of Neuroscience.

Child's play. An Iowa State University study found that 25 percent of children — ranging in ages from 11 to 16 — in low-income households reported having sex. The average age of first intercourse for that group was 12.