Heck, I didn't have a programmable thermostat for three years, in Atlanta, and would be surprised to see anywhere near these savings. I had a thermostat with a manual lever, which was mechanically coupled to a mercury-glass switch that controlled the A/C (this was a new apartment building built in 1999, strangely enough, not some ancient relic). I turned the thermostat way up (i.e. reduced the intensity of the A/C) when I would leave, and turned it back down when I got home. This by itself was enough to reduce almost to zero the operation of the A/C when I wasn't home, which was a pretty good approximation of the desired outcome.
