Useful GMaps GeoRSS Quirk

I noted recently that the Google Maps GeoRSS mapper acts on every location found in a feed. You can exploit this feature to set a map scale independent of the extent of the locations in the feed entries. Add a large bounding box location as a child of the feed, outside any entry:

<?xml version="1.0" encoding="utf-8"?>
<feed
  xmlns="http://www.w3.org/2005/Atom"
  xmlns:georss="http://www.georss.org/georss"
  xmlns:gml="http://www.opengis.net/gml"
  xmlns:thr="http://purl.org/syndication/thread/1.0"
  >
  <georss:where>
    <gml:Polygon>
      <gml:exterior>
        <gml:LinearRing>
          <gml:posList>
            0.0 -50.0 70.0 -50.0 70.0 -120.0 0.0 -120.0 0.0 -50.0
          </gml:posList>
        </gml:LinearRing>
      </gml:exterior>
    </gml:Polygon>
  </georss:where>
  <entry>
    <id>urn:uuid:7e8ee974-9181-4eae-ad65-55d29175d942</id>
    <link href="http://example.org/entries/1"/>
    <title>NCAA Men's Final 2008</title>
    <summary>UNC-Chapel Hill vs UCLA. San Antonio, TX. 7 April 2008.</summary>
    <content type="application/xhtml+xml" src="http://example.org/entries/1"/>
    <georss:where>
      <gml:Point>
        <gml:pos>29.422853 -98.493805</gml:pos>
      </gml:Point>
    </georss:where>
  </entry>
  <entry>
    <id>urn:uuid:53664db3-4598-45d4-a727-022c6203322e</id>
    <link rel="related" href="http://example.org/entries/1"/>

    <thr:in-reply-to
      ref="urn:uuid:7e8ee974-9181-4eae-ad65-55d29175d942"
      type="application/xhtml+xml"
      href="http://www.example.org/entries/1"
      />

    <title>UNC-Chapel Hill</title>
    <summary>This is the location of the UNC (http://www.unc.edu) campus in
    Chapel Hill. Related to: http://example.org/entries/1.</summary>
    <georss:where>
      <gml:Point>
        <gml:pos>35.914078 -79.056931</gml:pos>
      </gml:Point>
    </georss:where>
  </entry>
  <entry>
    <id>urn:uuid:2528d1b4-b5a9-415c-be69-f83974e3e6af</id>
    <link rel="related" href="http://example.org/entries/1"/>

    <thr:in-reply-to
      ref="urn:uuid:7e8ee974-9181-4eae-ad65-55d29175d942"
      type="application/xhtml+xml"
      href="http://www.example.org/entries/1"
      />

    <title>UCLA</title>
    <summary>This is the location of the UCLA (http://www.ucla.edu) campus in
    Westwood. Related to: http://example.org/entries/1.</summary>
    <georss:where>
      <gml:Point>
        <gml:pos>34.060623 -118.445663</gml:pos>
      </gml:Point>
    </georss:where>
  </entry>
</feed>

and GMaps displays the feed on a map zoomed out to encompass the bounding region specified for the feed.

http://sgillies.net/images/feed-location.jpg

Compare that to this map of the same feed with the top-level location removed:

http://sgillies.net/images/multi-entry.jpg

I'm thinking this quirk just might be a good practice.

Update (2008-04-6): So much for my finals prediction.