Steve, it's my understanding is that a "spider" is a search engine (probably used by a spammer to find available forums to log into to and create new accounts). It just roams the net looking for the forums.
It's hard for a database to distinguish the difference sometimes, but like Bob said - the major function of a spider is a program initiated by Google (or other high-level search engine) that crawls forums adding to it's database. Most of the time, it's a good thing...especially for a new forum.
When someone searches for "Fishing in Georgia" or "fishing tips Georgia" etc, etc, the more detailed info that the search engine has on-hand, the better. And the more hits GFF will get.
