In his article for the MSDN Magazine, Charles Petzold discusses Fluid UI and Silverlight and gives some nice examples.
In the past two installments of this column, I’ve discussed some techniques implementing fluid UI on your own. I was partially inspired by the upcoming introduction of a fluid UI feature in Silverlight 4. Now that Silverlight 4 has been officially released, that’s what I’ll be covering here. Silverlight 4’s foray into fluid UI is rather narrowly confined—it’s restricted to the loading and unloading of items in a ListBox—but it gives us some important hints on how to extend fluid UI techniques with our own implementations. More fluid UI behaviors are available in Expression Blend 4.