Pressure cookers are great! You can cook things in just a fraction of the time. And the food turns out beautiful. My sister is the gourmet cook in the family, and she turned me on to the joys of pressure cookers.
For data on the ton of money you can save:
http://fastcooking.ca/energy_savings...ure_cooker.htm
If you're interested in how the things work:
http://fastcooking.ca/pressure_cooke...okers_work.htm