From Oct. 2007: Expanding on my wife's list: (in no particular order)
Freeze water in reusable plastic bottles, add lemon juice and sweetener, reuse. Doubles as ice pack in lunch bag.
I’ve been reusing the same plastic spoon for my coffee for about three years. (I attach it to the side of my travel mug with a rubber band.)
Don't let faucet run while brushing teeth or shaving.
Hang up and reuse towels rather than automatically drop in hamper.
Conscientiously adjust water level in washing machine, use cold cycle.
Wash and dry before and after 8 when energy use is lower.
Lights out, TV off, appliances unplugged.
Compare length and mil when buying toilet paper. The cheaper store brand TP really is just as good.
Reuse large, plastic V8 bottle, but refill from less expensive can.
Put food processor on counter, make it easier to use bulk items, prepare in advance.
Buy bulk and prepare meals in advance reusing aluminum trays.
Rice cooker: makes perfect rice easy and convenient. Make in bulk and reheat for lunch.
Stretch ground beef/turkey with bread and oatmeal
Use smaller bowls and plates.
Make good use of the library - reserve movies music and magazines as well as books.
Download free audiobooks from Librivox, listen to Podcasts, Swap movies with friends and family. Host movie nights.
Rediscover what you already have. Reread books you own, enjoy old comics, and incorporate found objects arts and crafts into a favorite hobby.
Automatic cat litter box and clumping sand - refill bucket from bulk. Uses less litter and is always cleaner.
When directions for Craig's List and Freecycle - don't print color map. Copy and paste directions only into e-mail, print in black on reused paper, or copy onto scrap paper by hand.
Cancel catalog project, using pre-printed "Remove me" labels, cutting out addresses and taping them onto postage paid postcards. Bookmark website, subscribe to e-newsletters of anything you want to check in on.
Transition your taste buds by mixing name brand and generic versions until you've gotten used to generic. (In many cases, the real difference between your "preferred" name-brand product and the less-expensive version is considerable added sugar, salt or thickener. Modify yourself if you wish.)
Wash and/or rinse and put away individual pots, pans and dishes as soon as you're done using them, saving water, soap and electricity from the dishwasher.
Adjust your body temp with clothes and blankets before adjusting the whole house. Use windows, doors and curtains to moderate temperatures rather than automatically adjusting thermostat.
Use task lighting rather than whole room lighting.
If one person is a "nibbler" arrange for someone who is not to put away left overs.
Also, we ask each other every day, "Did you spend any money?" And we're proud to brag that we did not.