I've been looking for rain barrels for a while. I was able to find a cheap source of them on craigslist.
I already had one rain barrel. It came with the house. Now I have 3 more.
I leveled the ground and put down stone block. This got the barrels high enough that I'd be able to get a bucket or other watering device under them.
The two pictured above are on either side of my screened in porch. The one below is at the front corner of the house.
Collecting rain water in some states is illegal. Luckily, I don't live in those states. Here in North Carolina it is perfectly legal to collect rain water.