Running Windows Vista? Noticed the Windows CardSpace applet in the Vista control panel but not sure what its for? That may soon change if Windows Live ID provides CardSpace integration.

Formerly called InfoCard, CardSpace integration with Windows Live was discussed back in March 2006 when Live ID was first emerging as the updated Microsoft Passport. To put it as simply as possible, CardSpace allows you to securely store multiple identies on your PC, and use them online when required. This eliminates the need to enter a password when you want to identify yourself to a web service - instead you choose the identity you wish to send from your PC. This helps protect the user from phishing scams and keyloggers, which for more important services like online banking, helps reduce the risk of identity theft.

So how would this work for Live ID? Testers of the in-beta Windows Live ID authentication services SDK (which allows users to log into 3rd party sites with their Live ID) are currently able to create a custom signin page on the Windows Live ID test servers. This login page presents the user with the existing option to sign in with a Live ID, or the alternative - to sign in using CardSpace.

After selecting the CardSpace option, users are prompted to login to Live ID with their password, after which they are able to select an identity from Windows CardSpace to link to their Live ID. Once confirmed, this CardSpace identity then becomes the login credential you need, replacing the password you used previously. Of couse if you wish to remove or change your CardSpace identity from your Live ID, you can do so using your password.

If you haven't yet started looking at the Windows Live ID authentication services SDK, this is yet another reason why you should do. Part 1 of Colin's tutorial on how to add Live ID to your website is already available. Our favourite CS developer Nick is already working on this so you might see CardSpace integration over here at some point :)