Xaraya connects to worldkit
For play, i constructed a couple of templates on the Xaraya site to connect the Worldkit package to a xaraya installation to construct a geographical map (flash based) of the registered users on the Xaraya site.
Worldkit uses an RSS feed with location information to construct an image where the data points are shown on a map. In doing so, of course the RSS feed can be subscribed to in the 'normal' way too, giving you an addressbook directly in your aggregator of all people who have provided their longitude and latitude information on the site.