Read original post by Den Delimarsky at Den by Default
Out of the box, the Windows Phone SDK offers developers the capability to request user input with Guide.BeginShowKeyboardInput. This approach, however, can be quite limiting, depending on the situation, especially when the user does not necessarily needs to enter an item but rather select it.
That’s why I created the ToastPrompt control, a simple customizable message dialog, that can be used in tandem with the Windows Phone Toolkit to create a flexible input dialog that slides down from the top of the page and supports both text input, and selection input from a ListPicker.