The HD Big Box store sells a thermostat made by Filtrete that connects to your WIFI Internet router.. It allows you to monitor house indoor temp and adjust your thermostat via an iPhone app or via Internet web site remotely from anywhere in the world.
I installed one in my primary home and one at vacation home. they work great. Even when home I adjust the A/C from my iPhone at my bedside. When traveling between homes I can turn the A/C down before arriving so it is cool when I arrive.
It is Model 3M50 thermostat by Filtrete and it is only $99.00.
You can also change programs, set it to hold temp, change it from heat to cool, etc.