At my Photoshop seminars, I often zoom in on a portion of my screen so that people at the back of the room can read some of the fine detail in an image, palette, or icon. If you use a Mac and would like to temporarily zoom in on your screen, then do the following:
1) Choose System Preferences and then click on the Universal Access icon.
2) Click the large button labeled Turn On Zoom (that is unless it happens to be labeled Turn Off Zoom).
3) When you want to zoom in on a portion of your screen, position your mouse over the area and then hold both the Option and Command keys and then press + to zoom in. The more times you press that key combo, the more you’ll magnify your screen. When you’re all done hold the same two keys down and press – to zoom out.
I’m sure there is a utility available for Windows that has similar functionality, but as far as I know it’s not built into the operating system… if I’m wrong, please let me know where to find the feature.