By greimer on Jan 10, 2007
Hitting pixel-sized targets with a trackpad is a tedious chore, especially in Photoshop where it seems you have to do it every other move. Sure, your sweaty, corrugated fingertip can get you within a certain range, but trying to home in right on top of a single pixel becomes a battle against frictional physics and your own lack of motor skills.
Some devices, like microscopes and high-end radio tuners, have coarse- and fine-adjustment knobs, which let you get into range, then zero in, respectively. I found a simple technique that acts like a fine-adjustment for any trackpad. In any case it works on my Macbook Pro's trackpad.
The Fingertip Roll
Here's the trick: instead of trying to nudge the pointer onto the target by dragging your grubby digit over the surface of the pad, allow the weight of your hand to anchor the fingertip down on one spot. Then, by changing the yaw and pitch of your hand, roll the fingertip in the direction you want the mouse to go. With about four seconds of practice, you'll find that it gives you fine-grained, 360° control over a range of about five to ten pixels.
If you need really good mouse control, nothing replaces an external mouse. But inevitably you'll find yourself in a situation where you're stuck with the trackpad. This technique has been really helpful for me, and it's easy to get the hang of. Enjoy!