One of the great things about using WordPress is the search function. The search is easy to use and of course there are other more manual methods of categorization.
WordPress Search vs. Desktop Search
Spotlight for Mac is an excellent desktop based search tool that searches a pre-created index. Of course there is also Google Desktop Search.
WordPress Advantage
However, in our experience running a search on a grouping of WordPress posts is an even better of way of searching through large amounts of content. Furthermore the search can be run from any computer while Spotlight is computer specific. The effort is in the front-end when migrating unstructured content to a WordPress format, however, this combination of being able to search the blog from any location and precise searching is an unbeatable combination. Once a blog has been around for several months, oftentimes search results will appear in Google (for those articles which you do not password protect).
