One of the more interesting results in human sexuality was the study that revealed that women prefer the smell of men whose immune systems are the most different from their own. In the study, women were given a variety of men's T-shirts (used) and asked which ones smelled the most appealing. It was found they liked the most men who had different genetic immunities from their own. (I'm not sure just how they determined this immune system mapping.) This makes sense, we want to breed children with combined immunities -- opposites should attract in this case.

If the mapping is not too expensive, this seems like a good basis for a dating service. Of course do the other things dating services are doing, matching interests etc. But also add "chemistry" of which smell is an important though not complete part. Many people complain that computer dating matches them up with interesting friends but there is often no spark. A dating service that could offer chemistry as well as compatibility could do very well...

(Of course if the immune map is too expensive to build, one could do it the old fashioned way, with a gallery of T-shirts at the office. First find the partners you are compatible with in other ways, then pull out the shirts and see who passes the smell test.)

Note: I'm now back from Australia and at Foresight's Nanotech conference. Later I will be writing a lot about my observations in Australia, and later still putting up a large array of photos.