Marshall - 5:40 pm on Feb 1, 2012 (gmt 0)

<?xml version="1.0" encoding="UTF-8" ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
xmlns:mobile="http://www.google.com/schemas/sitemap-mobile/1.0">
<url>
<loc>http://mobile.example.com/article100.html</loc>
<mobile:mobile/>
</url>
</urlset>

More info [support.google.com]

Just an FYI - if your mobile version is on the same domain as your regular version, you may get warnings about duplicate titles or descriptions in WMT. However, I have not seen any warnings about duplicate content. Supposedly, using the mobile site map lets Google know it is not to be treated as duplicate content.

Marshall