I would encourage everyone who works with Silverlight to take a good hard look at Behaviors.  A Behavior is basically some code-behind logic that operates on Silverlight UI elements, bundled into a nice little package that can be in Xaml.  Behaviors can support parameters as well, making them both flexible and extensible.  In Expression Blend 3, several behaviors are provided out-of-the-box.  There is a drag/drop behavior, and a behavior that allows you to control storyboard animations based on events, just to name a couple. 

Below is a Silverlight example of a Rectangle that uses these two behaviors.  When the mouse enters the rectangle, it will alternate colors between red and yellow.  You can also drag the rectangle around.  Check it out…

And here is the Xaml representation of the above Silverlight application:

As you can see this is about 30 lines of Xaml that I was able to produce with simple point and click in Expression Blend.  Notice the elements that start with <i:…/>  These are the behaviors that control the storyboard and mouse drag.

The beauty of Behaviors is that they are so easy to use and are highly reusable.  They can also be quite powerful when combined together to create complex user interactions.

No self-respecting operating system type platform would be worth it’s darn without an implementation of good ‘ole Klondike solitaire.

Solitaire is included as part of available the current myOSity applications, and I’ve included the source code below, for those interested in how it works.

The real reason I wrote this was to have something half-way interesting to look at, and test with, while I was in the earliest stages of myOSity development.  It was also a proving ground to learn some basic UI mechanics of Silverlight (drag & drop, etc).  It could use a little polish (no designer here!), but it does the job.