Geotagging

I stumbled on an article ("Geotagging Web Pages and RSS Feeds") from the January 2005 issue of Linux Journal. Geotagging is adding geographic metadata to web sites or RSS feeds. For example, a blog entry about a restaurant could give the location of the restaurant in any number of standard ways:

• Latitude/longitude (otherwise known as "ICBM," a term dating back to the good old days of early Unix and the Cold War), or by street address, or by city, state, and country.
• Using Geo Tags — geo.position [latitude and longitude], geo.placename [natural-language name of the place], geo.region [ISO country subdivision].
• In RDF, the Geographical Vocabulary Workspace.

As the article points out, there are relatively few search engines that make use of this data, but among those that do are A2B and (for RSS feeds) RDF Mapper.
I haven’t been able to find a library making use of this technology, but a couple things strike me about it. Wouldn’t it be interesting to tag a local history or cultural guide with relevant metadata so that a search tool could pull together both information about the locations as well as where they are? Or to collect fiction set in the library’s home town and include, along with the reviews of the books, tags indicating where the book’s main action takes place?
Or, more broadly, simply tagging various library branches with geographical information might make it easier for someone to get from a GPS-enabled cell phone to your physical location — via your web site.