We recently got a programmable thermostat, something I've wanted for quite a while to save on our heating bill. When I asked our landlady, she and our handyman both thought it was a great idea, and they installed them in both units of our building last weekend.
I haven't had it long enough to know if I'll see an immediate difference in our heating bill, but I already love the convenience.
When I went looking to see if there are recommendations for actual temperature settings, I also found The Home Energy Saver Answer Desk.
The site has answers to common questions under the following headings:
~ Heating, Ventilation, and Air Conditioning
~ Comfort and Indoor Environment
~ Water Heating
They include answers to all sorts of questions, including those niggling things like, if I turn my heat down to 55 F, does it take more energy to heat back up than it would if I'd left it at 65 F the whole time? (No -- go ahead, and "turn it down when you're not around.") Or, how much energy does my answering machine use vs my computer? (You'll be surprised.)
Anyway, it's a great resource for all sorts of everyday energy-use and energy-savings questions.