I decided to write up a tutorial on using the clone tool. This tutorial is done in Photoshop 6, but I figure it would transfer well into the other photoshops.
First, let's run down what, exactly, the clone tool does. The clone tool basically takes a chunk of your image and pastes it over another chunk. By using a small enough brush and a little know-how, you can get rid of logos, blemishes, expand a picture's background, etc.
I'll be taking the text out of this image:
Clone Tutorial