Alex Golesh has posted two of his Silverlight 3 quick tips - the first one is about
Caret Brush and the second is on
DataBinding with validation.
Silverlight 3 provides validation mechanism while using Two-Way data binding. Silverlight 3 also provides default a Validation Exception UI – callout with exception details, which could be customized. Many input-related controls such as TextBox, CheckBox, etc. have built-in support for validation. How to use? Simple, like everything with Silverlight: To enable validation, use the ValidatesOnExceptions property.