FlickrXSLT

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:html="http://www.w3.org/1999/xhtml" version="1.0">
  <xsl:template match="/">
    <items>
      <xsl:for-each select="//A/IMG[starts-with(@src, 'http://photos')]">
        <item>
          <href>
            <xsl:value-of select="@src" />
          </href>
        </item>
      </xsl:for-each>
    </items>
  </xsl:template>
</xsl:stylesheet>