http://blogs.msdn.com/b/ericgu/archive/2007/11/08/extending-healthvault-data-types-using-a-custom-extension.aspxThis post will cover the second method of extending a HealthVault data type. If you haven't read about the first method , please do so now. We'll wait. In the first method, we had to deal with all the XML details ourselves, which made it a bit clumsyen-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)http://blogs.msdn.com/b/ericgu/archive/2007/11/08/extending-healthvault-data-types-using-a-custom-extension.aspx#6000164Fri, 09 Nov 2007 03:03:38 GMT91d46819-8472-40ad-a661-2c78acb4018c:6000164HealthVault<p>Two posts that explain how to add some custom data to an existing data type... Extending HealthVault</p> <img src="http://blogs.msdn.com/aggbug.aspx?PostID=6000164" width="1" height="1">