This favourite demonstration follows on very well from the flaming hand demo and is an excellent illustration of a combustion reaction.
There's no need to use propanol as suggested in the film as IMS/meths works just as well, if not better, and is much cheaper. As you prepare the bottle, discuss the mixing of the vaporised fuel with oxygen and be sure to make sure the class see you pour away the excess liquid fuel. When you light the fuel make sure it isn't too close to the ceiling and ensure the bottle isn't underneath a projector.
After the combustion reaction the bottle can be passed around the class so students can feel how warm it is. You can demonstrate the presence of carbon dioxide as a product of the reaction by showing that a lit spill goes out if placed in the bottle. Pouring out the condensed water (without soot if you use meths!) is effective for showing the other product of the reaction.
Students should now be able to write a word equation for the combustion reaction and go on to predict the equations for other fuels. If you have a second bottle, the reaction can be shown again at the end of the lesson if students work well enough! If you don't already have a suitable bottle in school, they can be bought via the internet at modest cost.