I have the very same original question - though my file is a 6 minute Premire Pro/Flash construct built HD 16:9 - it is small enough to fit the DVD disc, but I can't find any way to burn it HD 16:9. I have a Mac at home with Toast, but no DVD burner. Is Toast really the only way to do this?

Depending on your needs you can simply burn a data disc with that file on it. If you need DVD capacity on the disc though, you will need a DVD burner.