First I will show you the easiest way in Photoshop to create even, concentric circles and after we will ad an inverted text to make it look hypnotic in a groovy kind of a way.
Lots of people think using a layer mask is only for the advanced Gimp users, fortunately this isn't the case at all. Let me explain you the basic usage of layer mask on a easy to follow step-by-step example.
A simple Photoshop tutorial, where you may learn how to expose an object by leaving it in color while turning the rest of the photo black and white or sepia.
You can add multiple desktops to the Mac OS X Mountain Lion by using Mission Control, formerly known as Spaces. Can be really useful if you are a busy multi-tasker.