Research increasingly suggests that body odour is much more than a sign that you need to shower. A recent study from a team at Poland's University of Wroclaw found that volunteers who smelled shirts belonging to "odour donors" could detect the owners' personality traits with a surprisingly significant degree of accuracy. Specifically, people were able to predict how socially dominant the odour donor was, how outgoing he or she was, and how anxious or neurotic.
The team in charge of the experiment also found that the participants were particularly good at predicting how dominant members of the opposite sex were, suggesting that people may pay particular attention to this trait when looking for a partner (no word on smell and same-sex couples yet, unfortunately). It would be interesting, as well, to see whether the fragrance you wear may also help express your "smellable" traits, the way it's known to enhance your natural immune-system-related odour.