Here are some simple key commands you can perform while using iTunes:

Command-T (Mac) Control-T (PC): Turn the visualizer on or off.

Command-F (Mac) Control-F (PC): Toggle Full Screen mode on or off.

When the visualizer runs you get a small button on the top right portion of iTunes labeled 'Options'. Click this button to access these additional settings:

Check the 'Cap frame rate at 30fps' to prevent iTunes from using too much processor power and slowing down other functions on your computer. Check 'Faster but rougher display' for slower computers so that the visualizer doesn't get all choppy.

Here are some additional key commands that can be performed while the visualizer is running. They'll give you more control over what you see, and you can even save your favorite configurations:

-Press the R key to change the visualizer to a new random one.

-Press C to display the current foreground, background, and color settings (see graphic). You can see that each visualizer setting is actually made up of three things; a foreground pattern, a background pattern, and a color.

-Press Q or W to cycle through the foreground patterns.

-Press A or S to cycle through the background patterns.

-Press Z or X to cycle through the colors.

-Press Shift + 0-9 to save a visualizer combination. When you want to recall and watch that configuration just press the number key.

-Press the M key and it will enter three display modes: 'User config slideshow mode' will go through your saved settings, ''freezes current config' will hold this visualizer, and random slideshow mode will let it do it's thing like normal.

Depending on the change made, there will sometimes be a delay while the visualizer makes a smooth transition to the new setting. So be patient if you press a key and it doesn't seem to work. Also, some of the changes are very subtle so you might not notice that it has changed even though it actually has.

There is one thing that I don't get about the iTunes visualizer - why does it continue to move when you pause the music? It seems to me that the visuals should pause along with the music.

In addition to the aforementioned controls to modify your visualizer experience, there are quite a few 3rd-party visualizer modules out there that you can download and install into iTunes. Some of them suck, some look a lot like the default Apple visualizer, and some of them are pretty great.

Now, I can't be held responsible if you spend 5 hours at work today staring at the visualizer and drooling.