Whenever you are developing a silverlight solution on SharePoint 2010, one of the basic functionality you will require is the ability to select people from your Active Directory.
Sadly, I could not find a ready made custom silverlight control which I could utilize for my solution. I decided to write on my own. Rather than writing from scratch, I decided to use the boilerplate code provided by Steve.
This project contains a Silverlight People picker and People Chooser WebPart
See accompanying blog post for more information on how this controls is built - Writing Silverlight people picker control using SharePoint 2010 Client object model