I love to see it rain here in the Arizona desert. We are always in such dire need of it. The other day it rained and I went out in the backyard to see how the gardens were doing. While looking around, I noticed my rain barrel system was still working flawlessly.
I bought a dozen or so rain barrels (rinsed out 55 gallon used Coke barrels) and placed them on the side of my house. The back of my roof is pitched and has two gutter drains dumping right outside the back wall of my house. I placed a barrel directly under each drain and to my joy, had them filled in no time.
Here's a little video: