My husband has always wanted to have a rain barrel! He noticed that our city was selling them (for cost), so we picked one up. He set it up the other day. We have only had one good rain so far this month, but it filled the rain barrel completely to the top.
I used it for the first time today, and I have to say, it's just the ticket. It has a lid, with a mesh screen to keep mosquitos out of it. He set it up so that rain water from the downspout on our garage goes directly into the barrel, through the mesh screen.
The best part about it is this tap at the bottom. He raised the barrel up on blocks so that my watering can fits perfectly underneath.
We feel this is very good, environmentally. We have a well, but using the rain water saves the electricity to run the pump as well as the ground water.
Plus it's fun!