We water our gardens with harvested rain water. The first photo is the two 250 gal. cubes that collect water off the barn roof. The second is a 55 gal. barrel that collects off the house, and the last is a close-up of one of the cubes that we have collecting water off the garage roof. With 1/2" of rain, we get about 800 gallons of rainwater saved.
I dip (from the barrel) or pour (from the cubes) and carry to the plants. We have three vegetable gardens, an asparagus patch, and four flower beds (I also have magnificent biceps from the carrying). I find that dipping and carrying lets me know just how much a plant needs, and how well the plant is doing. We do have an attachment on one of the barn cubes that allows me to hook up a hose, but we have only had to use it twice, during the drought of 2011.
Our hens are also watered from the harvested rainwater.
Our rainwater harvesting system is not cost effective after you factor in the cost of guttering, but in Texas it is only a matter of time before the cost of water is not the question, it will be the availability of water. At that time our system will be cost effective, as well as necessary.