You can search by username (i.e. jondclarke), and the user’s name (i.e. “Jon” or “Clarke”), but that’s all at the moment. We have no facility, for instance, of searching by geographical area. It was planned to add this for the administrators so that we can analyse usage of the website.
Is this something that you would like as well? How about other users – what searches would you like to be able to do?