Where can I find a fire ring for backyard campfires?

I can point you to a few of the many resources on the Internet, but first, think about this: where have you seen a campfire ring that you like? at a state park? some campground while on vacation? Every state or national park/forest campground I have ever been in has those big iron rings for campfires. You could ask them if there is a local manufacturer that they get them from. Or, you can check out these Web sites:

Pit-2-Go

PilotRock Campfire Rings

J.M.S. Tooling Fire Ring

Also, check under "park supplies" in the Yellow Pages.