I did - I actually bought a finished rain barrel from a guy who makes them, who had a booth at our local plant sale last year. It's I think 33 gal? The kind that's white with a red lid that can screw on and off. The lid has a hole cut in it with a piece of regular window screen attached to filter out debris, and towards the bottom is a spigot you can attach a hose to. It also has a clear tube on the outside that fills from the bottom, so you can see the water level without removing the lid. It has an overflow tube, so when the barrel is full the you can direct the excess water into another barrel, an animal water trough, etc. I have two large trash cans they were giving away at work to hold the excess water.
When I built the roof on my chicken coop, I put a gutter on it and made the downspout exit the chickens' yard and empty into the rain barrel, and set the barrel on concrete blocks so it's about 2' off the ground. The two overflow trash cans aren't covered, so I get the chickens' water out of the spigot on the first barrel, use the second barrel for watering plants, and the third barrel for cleaning/rinsing things - I keep a scrub brush on a cord attached to the barrel's handle, which is really convenient for cleaning the chickens' waterer, plant pots, etc.
The rain barrel I bought for $60, which was a bargain - probably not much more than it would cost to buy all the materials to make one, not to mention the time spent and learning curve to make it not leak. But it wouldn't be that hard to make one, especially now that I have one to copy. You could also make a simpler one, with just the screened lid and bottom spigot, which would work great. All my pictures just show it in the background, but I can get better pictures with close-ups of all the parts if you're interested.
I often see free/cheap used cattle or hog panels on Craigslist, but more often, people who have partial rolls of used or leftover field fencing they just want to get rid of. Those do a good job, attached to T-posts.