WFMW - Good deal for laundry soap

A while ago I waxed eloquent on the frugality of the laundry soap available at Sears. While that is still a great deal if you can hit a sale, an equally good buy can be had at Walmart 24 hours a day.

Lately we've been buying big boxes of Purex for just under $3 a box. No coupon is going to make Tide that cheap!  We can get away with using 1/2 to 3/4 of the amount listed on the box since we have soft water.

To anticipate a couple questions...We do have sensitive skin around here and have experienced no increase in itchies over the past 6 months of use. It is rated for H.E. washers. I have 2 front-loaders, and it works just fine. The clothes are just as clean as with other soaps I've used. The box states it's good for 30 loads, but I know we get more than that out of it. 4 boxes last us about 2 months doing about 18 large loads/week.

What do you use to make your laundry life easier or cheaper?