Thanks again ... I guess it doesn't really apply to the stuff I do. Referring to the example I posted, which is a real-life address (the realtor.com one) ... don't search engines crawl your site indexing the urls of the pages found? ... and, if this is true, how does the search engine crawl what appears to be a folder address? Are they creating a separate file for every property they have in the database?

If they add a new property to their site (to their database) whose address is '25 Acacia Avenue' they have to go to the trouble of setting up a url rewrite (for every property)? Or is this done automatically somehow?