Treat it the same as nightclubs. No single males admitted, you have to come with a female friend. If you don't have any female friends, well, that may be an indicator that you don't have enough social skills to attend a conference (or perhaps, that you should spend some time getting female friends rather than wasting it on computer stuff). Invited speakers and sponsors could be exempted from this requirement. Then the sex ratio will be close to 50-50 and the whole atmosphere will be quite different.
I have to admit that it could be hard to find enough women interested in kernel memory management. So the content of conferences might have to change a little bit to attract a better balance of the sexes.
Failing that just have separate conferences for men and women.