One tool I can't live without is a real lifesaver, and it serves a dual purpose. Keynamics makes a nifty little device that's super simple -- and super useful.
The Aviator Laptop Stand is intended to be used on planes, so you can rest your laptop on a seat tray and not have to hunch forward to work. But I've found it to be the best laptop stand for everyday desk use bar none.
It keeps your laptop off the surface of your desk, which increases airflow around the computer and aids in cooling. It also tilts the laptop forward gently for a more ergonomic approach to the keyboard.
And at $20, it's super inexpensive. Just three pieces of plastic you can snap together. I've used other laptop stands -- metal, padded, all much more expensive -- and this one's the best.