Silverlight rather oddly lacks a double click event. You can detect single click, but for double clicking you’re on your own. I found some examples for C#, but none for IronPython and had, a few months ago, ported some code I found here for IronPython.
I’ve been using it in application development and user testing for about 6 months and it works fairly well in both Silverlight 2 and 3, although YMMV.
You may want to tweak the click interval based on what works for you. 500 milliseconds worked well with my users, for the application in question. To attach a ClickHandler simply invoke the static method ClickHandler.attachDoubleClickHandler(«uiElementObj», «callbackFunc»)
It’s not the world’s greatest solution, but it gets the job done.