I have had two rain barrels (that I purchased at great expense from Home Hardware) for two years now. They have been increddibly useful thus far.

This year I'm adding three of my own barrels. I purchased used 55 gallon food grade barrels from a local supplier. I will be daisy chaining these off of one of my other barrels. My hope is that these will last a lot longer than one barrel alone. Last year I constantly ran out of water and had to resort to using municipal water on my gardens!