Howcast - Parkinson's disease is a chronic condition caused by a lack of dopamine in the brain. Diagnosis can sometimes take years; knowing symptoms can speed up the process.

Howcast - There are times when it's to your advantage to use plastic.

Howcast - The density of salt water depends on how much salt is dissolved in it. Calculate the density of a particular sample with the method described here.

Howcast - It's a friendly social greeting you've seen a million times. Somehow, when you do it, you still feel awkward. Learn the correct way to cheek kiss once and for all.

Howcast - Dipping a woman is a great way to impress your peers on the dance floor. These steps will show you how to do it with style.

Howcast - A total body workout is a great way to keep your entire body fit and toned, leaving you with a complete sense of balance and accomplishment.

Howcast -If balance is what you crave in your life, apply these techniques from the Dog Whisperer and put yourself and your dog into the right relationship.

Howcast -Know your strengths and the staying power of your business concept before taking the leap.

Howcast -If stiff muscles are holding you back, this guide will help loosen things up and improve your athletic ability in a flash.

Howcast -This fun experiment will teach you how to find the center of gravity for any household, long-handled broom.

Howcast -If you've grown weary of that boring water workout, this guide will up the intensity with a routine that incorporates all the benefits of pilates in the pool.

Howcast -Learn how to skate backwards on rollerblades from in-line skater Tim Phang in this Howcast video.

Howcast -Learn how to balance on your rollerblades from in-line skater Tim Phang in this Howcast video.

Howcast -Learn how to shadowbox from boxing coach Joe Huston in this Howcast video.

Howcast -Learn how to work out with a punching bag from boxing coach Joe Huston in this Howcast video.

Howcast -Learn how to choose golf shoes from golf pro Michael Samaniego in this Howcast golf video.

Howcast -Learn how to do a tech deck manual in this Howcast video.

Howcast -Learn how to handle hot handblown glass safely from glassblower Todd Hansen in this Howcast video.

Howcast -Learn how to lose weight on the Eat Right for Your Type diet from Carolyn Dean, M.D. in this Howcast video.

Howcast -Learn how to prevent sliding down the pole from pole dancing instructor Mai Yee in this Howcast video.

Howcast -Learn how to grind on rollerblades from in-line skater Tim Phang in this Howcast video.

Howcast -Learn how to do a handstand in this Howcast video with Dulles Gymnastics Academy.

Howcast -Learn how to do a fast slide on rollerblades from in-line skater Tim Phang in this Howcast video.

Howcast -Learn how to read a hand's "three worlds" from psychotherapist and palm reading expert Ellen Goldberg, M.A. in this Howcast video.