My father and I are thinking about getting a 1500 gallon tank from here. http://www.plastic-mart.com/class.php?item=3444 And setting it up to catch water from the garage gutters. The Hay Bale growing system we used last year took quite a bit of extra water.
last time I tried to do a rain barrel I got a Mountain Dew syrup barrel from the bottling plant in Clarksville, brought it home, set it down in the yard and that night the Flood of 2010 hit. barrel's probably in Paducah by now.
Didn't get it directly from the bottling plant, should have made that clear - it originally came from there, but I bought it at the Habitat for Humanity store in Clarksville, believe it was just $10. That was the first day the place was open, though, price may have risen since. You could always get some plastic pipe and fittings & connect several together.