Work Out at Home. Try working out at home for free. It's amazing what some people can accomplish with only body-weight exercises and light weights.
Negotiate. The rates at most gyms are negotiable. Don't pay the asking price.
Don't Commit! Don't pay for a whole year until you've proven that you'll use it. And like the prices, initiation fees are negotiable. Ask for a month-to-month membership with no initiation fee.
Insurance Rebate. Some insurance companies give rebates on gym memberships. Worth asking about.
The European Way. Americans spend more time in gyms than almost any other country. Unfortunately, we are also one of the fattest countries. So what gives? Outside of the US, more people stay healthy by walking instead of driving and eating moderate portions of healthy food. If you have a healthy lifestyle, you won't need a gym.