 
Michael Crump discusses the creation of a Silverlight web application that could be used as a self-promotion/marketing tool.
Source: Michael Crump's Blog
I’ve always believed that as a developer you should always have a hobby project going on. I think a hobby project needs to contain at least one of following things: 
    • Something that you have never done before. 
    • Something that you are interested in. 
    • Something that you can work on in your spare time without affecting your *paying* job.