I discovered this while reading a blog that had a subject area on the recent banning of phosphates in detergents of all sorts, which makes cleaning of everything more difficult. Some silly ecological thing. If you're tired of running your dishwasher twice, buying this might be worth it.
Walgreens sells a 65 oz. box of this for $2, discounted from $3, on a regular basis. It's a powder, for dishwashing. There's also a liquid available for dishwashing in the sink.
And, apparently, it works really well. I picked up a couple boxes, lemon-scented, even. It's made in Salt Lake City and American Made is a good thing. Haven't tried it yet but I will once I run out of Cascade tabs or on the next batch of dirty dishes, whichever comes first.
UPDATE: It works! It really works! Cleans better than Cascade and no spots or streaks.