The Instant Alpha tool in Apple's Pages allows you to remove an unwanted background color from an image and make it transparent. This magic-wand style tool, once exclusive to the world of Photoshop users, is now freely available to anyone within Pages, Keynote and also iWeb.
This enables you to effortlessly create alpha images without using a separate application. You can use this feature to give your documents a professional layout by having text wrap around an image. Moreover, the process is fun and quick to achieve! Here's how...
Let's pick a picture. I've taken one from MorgueFile.com where many of the images are free to be remixed and used commercially. Here's a simple image with a white background:
The trick is to choose a picture with a single color background and where there is good contrast between the background colors and the area of the image you wish to preserve. A silhouette will be extremely easy to work with, but with some practice you can use more complex images and achieve great results too.
Drag the image into a Pages document and position it where you would like it to appear on your page.
Choose Format > Instant Alpha from the menu
Position your mouse cursor over the background of the image and the mouse cursor will turn into a crosshair.
Click on the color (or plain background) and drag to select the area to be removed. The more you drag the greater the area selected. This selected area to be removed will turn gray.
If you find you select parts of the image you don't want to remove, undo, then carefully drag less and release the mouse button and then repeat the process until all the unwanted color or background has been removed.
When you are happy with the results click outside of the image.
Play around with these settings to find what works best for your document to help you achieve the design-style you want!
Want to learn more about the "instant Alpha Tool" check out the Pages'09 101 Tutorial!