Sue;

I'd just keep my eyes peeled. Here in Chester county you can find them at some antique/"Junque" dealers, flea markets, yard sales, salvage yards, gas stations, and even a guy in Gap, PA that just sells used plastic drums.

I'd also check the local swap sheet, aka "Pennysaver" or what you call the used producs flier in Frederick Co.

Cheers.
--Jim

BritishSue - you want to be very careful about those drums - most times the reason it doesn't pay to recycle them is that they cannot be decontaminated from the "stuff" that was shipped in them. Oils, detergents, cleaners, dry-cleaning supplies etc. Sometimes really toxic stuff - like dry chlorine.
Cheaper and safer to just get four big trash cans, put spigots in the bottom, seal in with aquarium sealer and presto -- rain barrels.

Try Pepsi-cola in Baltimore. According to Maryland DNR pepsi sells used 55 gal drums for $5 each. I keep meaning to call them myself but it's been so long since we've seen any rain...

Here is a link that might be useful: Instructions for cheap Rain barrel construction with sources

Thanks PaulaW for the link! For y'all in Texas and elsewhere, below is another link to additional sources.

Here is a link that might be useful: Approved Rainbarrel Suppliers

Also for Texans, found a 66-page dot-pdf file on rainwater harvesting, at this URL:

http://www.twdb.state.tx.us/publications/reports/RainHarv.pdf

Here's a source of inexpensive, no-frills plastic rain barrels.

Here is a link that might be useful: Rain Barrels

Sue, another source might be the Knouse Foods plants near Gettysburg, PA. Plastic drums that fruit conc. was shipped in. They have a liner in them, so as a rule the drums are clean enough to eat out of. Plants are in Inwood, WV, Biglerville, Orrtanna, Peach Glen (hdqtrs), Gardeners and Chambersburg, PA. Also Duffy Mott apple processing in Gardeners, PA may have them. They can be found on the lawn of a house (for sale) on the road from B-ville to Hanover and also on the road from Orrtanna to Arndtsville.