I found this video on the backpacking.uk.co website.
Similar to the Trail Designs caldera cone but not pot specific, and can fold up well for transport. Looks like it could be adapted to canister stoves, or alcohol or solid fuel stoves with the pot on a trivet.
It clips on to the pot rim, rather than the pot being supported by the cone, so the pot needs to be self supporting.
Fun project for a rainy afternoon
http://www.backpackinglight.co.uk/produ ... PageID=110