How to Add a Background Shape to a Keynote Slide
Mac OS X Snow Leopard makes creating a slide presentation easy, using Keynote. As you format your slide, remember that text often stands out on a slide when it sits on top of a background shape. Adding a circle or rectangle in the slide background might be just the touch you needed to complete your slide.
To add a shape as a background for your text, follow these steps:
Click the insertion cursor in the location you want.
Don’t worry too much about placement. You can fine tune it later.
Click the Shapes button on the Keynote toolbar and choose a shape.
The shape appears in your document.
Click the center of the shape and drag it to a new spot.
As with image boxes, shapes can be resized or moved.
When the shape is properly positioned and sized, select it and choose Arrange→Send to Back.
The shape moves to the background.