I saw this in an article on Yahoo about green home made cleaners. I was intrigued by the dishwasher detergent, I have all of the ingredients already except the lemon kool aid.
• 1 cup of borax
• 1 cup of baking soda
• ¼ cup of table salt
• 2 packets (half an ounce) of unsweetened lemon Kool-Aid
You can try to save even more by buying ingredients in bulk, but another idea is to find smaller and much cheaper boxes at your local dollar store: a good idea to since you'll want to try a small amount at first to see if you like the results. The amounts listed above are good for 16 loads -- one tablespoon each -- so even small batches will last a while.
I plan on making a batch this weekend after I go grocery shopping.