Now would be a great time to get your A/C tuned up. If your unit is over 10 years old you might want to think about replacing it. Units that old cost so much more to operate, You can save 30% to 40% or more in cooling cost by replacing now. Plus the maintenance on an older unit is much higher than a new unit.
Tip from Tim: When you decide to replace your heating and air unit always get at least 2 different reputable contractors to give you a price. Cheaper is not always better, get references and check BBB.org before hiring anyone.