Drag & Drop Dashboard Instructions

If you’re using OS X 10.4, here’s something you may not have realized about Dashboard: It supports drag-and-drop. Many widgets will accept dropped objects; for those who like using drag-and-drop, this is welcome news. Dragging text and images to Dashboard is just about as a simple as dragging them anywhere else—just select the object or text you wish to drag, click-and-hold, start dragging, press F12 to activate Dashboard, and then navigate to the desired widget’s work area and drop the selection. Note that the desired widget must already be open in Dashboard; you can’t open a widget from the Dashboard bar while dragging something.
Source: Mac OS X Hints