A coworker showed this to me. A typical load of laundry costs about 70-75 cents (a lot more with Tide) and this will make it for a penny!

Washing soda and borax sound hard to find, but they're really not -- you just haven't looked for them before.

Here's what you do: equal measure of both, then use a cheese grater to add some flakes of Fels-Naptha (it gives it scent and a little suds). That's it! Add about a tablespoon of the mixture per load. Works like a charm.