Should I turn my air conditioner off while I'm gone during the day?

The quick and simple answer is NO. In the 100+ degree days it's best to turn your system up only 2 degrees warmer than you'd like to set it at when you get home from work. If your system has to work itself to death in order to cool your home down when you get home because you set it too high before you leave for work, you're not gaining anything. Your best bet is to get a programmable thermostat which will automatically have the house cool when you get home.