For anyone with high-efficiency front-load washing machines, the VERY high cost of HE laundry detergents seems to somewhat offset the energy savings. Not a problem according to the article linked below. Yes, I will now be using just a tablespoon of soap for loads of laundry that are only minimally dirty. Favorite quote from the article: "Generally, a tablespoon is enough for a load.... Any excess could result in mildew and damage to your machine."
YES! But How?: Green Washing by Kelly Shea — YES! Magazine