Watergems^(TM) are an amazing product.  In their dry form the look similar to large salt crystals.  Add one Tablespoon of the crystals to 1.5 gallons of water and they swell to absorb the water.  They have a huge variety of uses.  Use them in your decorative centerpieces when you want fresh flowers but can't have a pool of water.  Add food coloring to bring out the beautiful colors of your floral arrangement .  Freeze them and use them to keep your wine or champagne chilled.  Put them in potting soil to keep plants hydrated in between watering.  These little crystals swell to absorb water and then slowly release the water as needed.  In between uses just let them dry out, and then rehydrate them for another application.