This counpany manufactures and sells HYDROSOURCE, cross-linked polymer. Their site says it: absorbs water and nutrients, making them continuously available to plants. It reduces labor of garden preparation, watering, weeding, and pest control. It greatly increases growth rate and food production.
These are the similar water-absorbing crystals sold elsewhere at twice the price. I just purchased a 5lb. box that will greatly reduce my watering requirements for planters, windowboxes, hanging baskets and sacks.
Ordering is a bit annoying because you have to call it in (albeit toll free). Still, the price is great and the shipping charges are minimal.