GetXML Plugin for Movable Type: Ouch, this is a good plugin. There’s no limit to what you can do with this.
This Movable Type plugin implements a set of template tags for retrieving data in XML format and displaying the data on your MT-generated pages. […] The plugin will work with any well-formed XML document that can be retrieved via an HTTP GET request.
Connect a template with this stuff to the MT-Rebuild script and you could retrieve XML on a schedule, format it up into HTML, then include it all over your site, all with Movable Type. The utility of it is giving me a cramp.