If you have version two, try the text and background tab. For example dragging the elliptical circle to the Video Overlay row may give an effect close to what you're looking for. Remember to drag the effect to cover all the frames you want it applied to.

You can also click on the FX button on any event (scenes you drag to the timeline) then do something under Pan and Crop. Combining the overlay and doing a little cropping can give you some interesting effects.