The Natural Wave is a ceramic tray that works a lot like a hot plate when it's placed atop an active radiator — no need to plug it in. Just pile on any goodies you want warm — coffee, hot chocolate, muffins, your breakfast and the like — and enjoy them throughout the day. I've got a radiator in my room which sits right under a window, so I can imagine pulling up a chair as we head into more wintry months and enjoying some hot treats while taking in the view.
The Natural Wave has teeth that'll slot between the pipes of your radiator and, as most exposed radiators are about the same in design, it should fit most of them. The bad news? The Natural Wave is only a concept right now, though hopefully someone will pick up Byung-seok You's idea and run with it.