Rain catchment links

Mostly for my future reference -- I'm interested in getting two of these eventually (still deciding on type):

http://www.rain-barrel.net/rainwater-tank.html
http://www.composters.com/docs/rainbarrels.html

Also trying to figure out exactly how to restructure the downspouts so they go to the catchment barrels, and if that entails buying an additional downspout piece, and if so, exactly how long it should be and how to install it. I guess I'll have to get the barrel first so I can see how tall it is.

I liked the fact that these (as opposed to discarded Pepsi berrels etc.) have a threaded spigot where a standard garden hose can be attached and the water used regularly (avoiding mosquitos). The water would also need to be treated for mosquitos with something that won't contaminate or hurt plants.

The Diverter also looked useful.

Without purification/filtration attached, the water would only be used for gardening.