This is getting a lot of press lately, but it really is the best way to make versatile coffee that requires little effort from you in the groggy state of waking up.
At our house we make 5 quarts at a time, which for two moderate (to heavy) consumers lasts about ten days-two weeks. Start with an 8 quart container, add 2 quarts of ground coffee (about 24 oz of coffee), pour 6 quarts of cold water over it. Give it a good stir, cover and let it sit 8-12 hours, ideally stirring it a few times during that time–in the last couple of hours don’t stir it. When you’re ready, strain it through a combination of cheese cloth and coffee filters. If you can pour the liquid off without getting too much grounds for the first few quarts it will make the whole process go faster.
Depending on how strong you like your coffee you can dilute it with a 1:2 ratio or coffee to hot or cold water or up to 1:1. Eh voila! Coffee is ready.