Membership does have some advantages, and being able to easily search for past posts is one of them.

For some Guest posters, a search on the name of the person with whom one argues debates regularly should significantly narrow the search - unless that someone is also Guest.

Most who have been around long enough to have much to search for should have a good idea of a few people who are fairly often interested in the same things they are. This method also gives one a chance to learn what other bizarre things are of interest to the people who seemed so rational when they agreed with you.

John