You won't want to put this down.

We just can't let a good thing go. So when we found the DFX Sports & Fitness Pro Gyro from a Cali company, we refused to let it slip through our fingers. It wasn't so easy. The thing is like a mechanical bull for the hands.

Here's how it works: it's a plastic ball with a gyroscope inside. Start the gyroscope spinning with a flick of the fingers (it comes with a CD tutorial) or rev it up with the electric Powerdock. Then pick up the ball, circle your wrist and hang on tight. The DFX Sports Pro Gyro pulls wildly back and forth as the gyroscope spins inside, working your forearms and hands. Hold it out to the side, and you'll activate your shoulders. Just a minute was enough to make one editor's husband break a sweat.

We learned that this tool is often prescribed by physical therapists to heal sports injuries and carpal tunnel syndrome. You'll fire up your heart, and probably find yourself giggling, too.

Oh, get a grip.

Know someone who should grab this? Forward her this email!