1. Stretch During Loading Times

Playing a game on your computer? Stand up while it loads and stretch out. It feels good. Do a few curl-ups or push-ups instead of staring at a bar that slowly fills up, no matter how enthralling it is. If your computer crashes, take it as an omen that you need to walk around a bit while you reboot it. Turn your anger into productive physical activity.
2. Perform Simple Exercises

I'm sure you've all heard of these and ignored them. You shouldn't - they're so easy and don't impede you at all. I'm doing one while writing this article. Some of the simplest are these:
- Calf stretch: Just lift your toes off the ground a few times.
- Arm stretch: Take a break from typing and lift your arms high above your head, to the side, wherever. Get those kinks out.
- Leg stretch: Just lift your legs up. It's good for them.
- Side stretch: Place your arms above your head (as per the arm stretch) and just lean over left, right, and forward.
- Neck stretch: Just bring your head around slowly in a full circle, no drastic movements.
There are many more. Think of any easy ways to get yourself moving, even if only for ten seconds.
3. 20/20/20 Rule

A simple guideline while you're using the computer is for every 20 minutes you use the computer, look about 20 feet away for 20 seconds. Just take a break from staring at your computer screen for a bit. It's good for your eyes.