There are several sites with lots of recipe lists for homemade laundry soap. Why bother?
It's cheaper. Lots cheaper. The Simple Dollar reports a $70.00 savings and provides a per load savings comparison to bulk buys at Sams and Costco here.
Another factor is that making your own laundry soap means you know what's going into it, which can really help with skin allergies, eczema, and the like. Artificial fragrances alone are the source of many skin irritations.
For recipes, check out:
The Frugal Shopper
The Family Homestead