The "Green" on Dish washing:
-- A study refered to in treehugger.com proves that the dishwasher uses only half the energy and one-sixth of the water, less soap too than hand washing. see more on this debate: hand vs. machine washing
-- Set your machine (if possible) on a low energy setting, low heat setting. My dishwasher has 3 options: Hi-Temp Wash (on or off); High-Temp Rinse (on or off); Heat Dry (on or off) - mine are all set to off thereby maximizing my energy efficiency.
-- Run your dishwasher only when you have a full load.
-- Use biodegradable soap with no chemicals
-- Don't use a commercial rinse agent (again full of chemicals) I use good old vinegar as my rinse agent. My dishes have never looked better.
Here's to the dishwasher - thank goodness it is a green choice, as I would not enjoy washing dishes by hand.