I don't know if this is what you meant, but you can make an "out of browser" application with Silverlight 3; see for example
http://silverlight.net/learn/learnvideo.aspx?video=187318 and
http://msdn.microsoft.com/en-us/magazine/dd882515.aspxAs a note: this forum is intended for discussion of the Visual Studio designer for WPF and Silverlight, rather than the WPF and Silverlight platforms themselves. For WPF platform questions you'll usually do better trying
http://social.msdn.microsoft.com/Forums/en-US/wpf , for Silverlight platform questions try
http://silverlight.net/forums/Thanks
Mark
Mark Wilson-Thomas - Program Team - WPF & SL Designer for Visual Studio - posts are provided 'as-is'