Water is normally a function of the municipality or a corporation. So the decentralization of water gathering by the individual is a threat to these water authorities. Water laws differ everywhere one goes. In Colorado water rights are doled out on a seniority basis. So one does not own the water that falls on ones roof because it belongs to someone down stream because he was there first. These rights are sold back and forth. I think they are slowly liberalizing water laws there and have freed it up in rural counties. In New mexico, all new construction in the rural areas are now required to have rainwater collection. Here in Texas surface water belongs to the state and ground water belongs to the individual landowner. We are allowed to collect water but it is looked down on by the water authorities and their is talk about taxing roofs since they are "stealing surface water from down stream water authorities. It doesn't mater that only tree % of rainfall ever finds its way into a stream. Yea, I am passionate about this. I live totally of the water that falls on my roof. The idea is growing but at the same time there are new water laws on the Federal level that will take control of all streams, all water tanks, and anything that holds water like cattle tanks and cisterns. I am not totally sure about how things are worded there or if they will ever pass, but what I hear is not good for the small individual water collector if it goes through.

Hmm, I'm considering purchasing a tank. I think this one (especially since I'm in TN).
http://www.tank-depot.com/productdetails.aspx?part=TC8652IW

I believe it will fit nicely on the concrete floor in the basement. What do you all think?

I would like to connect it to the gutters with a diverter valve. I would only use it for watering the garden though (...too many military jets spraying chemicals in my area).