One of the problems I often see with some of our products is that they actually have some great features but not enough people know about them. Sometimes I am meeting a customer and he or she is telling me that they are just running an evaluation for a new piece of software. When you talk with them, they simply do not know that they actually already bought this functionality – with Windows. One of the examples is the Radius server. Often I met customers using Radius and having spent quite some money – without knowing that Windows Server already has one (for those who are looking for it: It is called Internet Authentication Server (IAS) or Network Policy Server (NPS) in Windows Server 2008).
Another example – however newer – is Windows Cardspace. A cool part of the operating system that helps the user to get back control over his or her personal information as well as passwords.
The best starting point for you to understand how Cardspace works is the One-Minute-Demo you will find here: https://channel9.msdn.com/Showpost.aspx?postid=306082
If you like to get more information on Cardspace, the best starting point is: http://cardspace.netfx3.com/
So, get familiar with it – it is a great technology to be used and give the user back control in the Privacy space as well as helps to prevent phishing
Last but not least, if you would like to use Cardspace with your Windows LiveID, there is the how-to: http://winliveid.spaces.live.com/blog/cns!AEE1BB0D86E23AAC!931.entry