Today a fast and easy tip about shadows and performance. In a project I have recently made, we've told the designer not to use BitmapEffect because they are performance killer. He so decided to create it's own shadows by duplicating each shape and make them looks like shadows. I was then surprised to see that it kills performance too ! There is still the shaders effect which came with the 3.5 SP1 framework but they will be available only on vista or greater plateforms and their performance will depend of your graphic cards. But we have an another ace in you deck : the system shadow which are quite fast even on software rendering!