Here's a little preview of something I'm just about done with. It's pretty self explanatory. It's a screensaver gadget that will allow you to select a screensaver to display. Here's a screenshot of it using the ribbons screensaver from Vista.
http://blogs.msdn.com/photos/markhsch/picture1718045.aspx
-Mark
New gadget teaser
Chester03
Robert3234
Brant Yin
As for passing mouse events back, so drag is possible. I'm not sure it's possible, unless there's a way to cancel event handling in a usercontrol class. You could try canceling then onmousedown event, but I doubt it will have the desired result:
protected override void OnMouseDown (MouseEventArgs e) {
e.Cancel = true
}