I spotted the Primus Fuel Canister Footrest on the shelf at Outdoor Pros and immediately purchased one. It's a simple design that easily snaps onto three different size fuel canisters and provides a lot of extra stability particularly when using single burner stoves.

The triple legs fold together for nice compact storage in your stove's carrying bag.

Not much to say other than it's a simple, effective, must have item for under $10 when cooking on any single burner stove that uses  these fuel cans.