Magnify screen on demand
How many times have you wanted to instantly zoom in on the screen? Well you can with Universal Access short-cuts in OS X.
Open your System Preferences control panel under the Apple menu. Listed in the System row is a preference panel called Universal Access. Click on the Universal Access panel to open it. Across the top is a row of tabs. Click on the tab labeled "Seeing."
Here you will see options for Zooming and changing the screen color for the sight impared. We are interested in the Zoom function. You can turn on the Zoom effect now by clicking on the big button labled "Turn On Zoom." If it says "Turn Off Zoom", then zoom in already on. Another way to turn on the zoom effect is with the keyboard short cut; command-option * at any time.
The zoom options button opens a sheet with other controls such as sliders for how much to zoom in and out on each step. I keep the sliders all of the way to the left at the first postion so my zoom is more controlable for each step. You can go ahead and play with these sliders to fit your need.
Go ahead and give it a try. Great for presenters when the audience has trouble seeing your screen!