Clipping Masks Tutorial Author - Onbrid (http://forums.biorust.com/member.php?u=303)

The most visually impressive Illustrator techniques are often based on the simplest principles. In this tutorial I will demonstrate how to cut text-shaped selections out of photographs (and other images), producing a solid framework on which to base logos, commercial artwork, or anything else that you desire.
 

Step 1: Create a new document with a canvas size of 800 by 600px. Choose RGB Colour and then press OK. Now paste in any image of your choice.  Try and be a bit more creative with your image choice than me!  ;)

Step 2: Type out your text and position it over your image. There's no need to outline or add any text effects now as this can be done later.  Besides, any outlines added now will disappear on the next step.

Step 3: With both your image and text selected go to Object > Clipping Mask > Make and that's it - you're done! The text is acting as a mask and you can see the image through the letters.

Step 4: Now to add a bit of personalisation.  Edit the text, move it around to display different parts of the image, add outlines or shadows etc. Note:  If you take a peek in your layers palette you'll find that Illustrator has created a Group which contains your text and image. You can use this feature to  move your image around and display different parts of the image through the mask without moving the text.