Just a suggestion along the lines of others that have been made in the past. When someone goes swimming, their scent could be overridden with a scent that is possibly semi unique to the pool they swam in.
This could allow for building a profile on someone's activities to make them easier to track down and target for RP. (Joe Baka always smells like Zesty Pool on tuesday, I should set up an ambush there to catch him).
