You can instantly zoom the screen in and out on your Mac. Place your cursor in the area where you want to zoom. Then hold down the "Control" key and move the scroll wheel on your mouse. As you move the scroll wheel up, it will zoom in. As you move the scroll wheel down, it will zoom out.

If you don't have a mouse with a scroll wheel and you are using a laptop, this will also work if you move two fingers side-by-side on the trackpad.

Try it now... it's really cool.