Blurring portions of an image with Photoshop is a snap. The most complicated part is figuring out which blur effect you want to use! There are a ton of choices including Blur, Blur More, Box Blur, Gaussian Blur, Lens Blur, Motion Blur, Radial Blur, Shape Blur, Smart Blur, and Surface Blur. My personal favorite for blurring parts of an image is Lens Blur but all of them allow for adjustment as well so you can make the blurring effect more intense or less intense. Click more for images of how to blur a section of your image with Photoshop CS2.
You can see in the second image the center box is blurred out. This blurring effect is really useful for blocking out personal information when posting photos on the web.
Below is a really good book on Photoshop CS3
If you haven’t upgraded to Photoshop CS4 you can purchase the upgrade below: