The above film was made by Microcoptervideo, a Spanish firm that specializes in shooting these types of films. It is of the Santiago de Compostela Cathedral in northern Spain and some of the interior shots are spectacular, although I wouldn't mind slapping the editor upside the head for some of his quick cuts and speeded-up transitions. (via Open Culture)
It was using an octocopter, which is a radio controlled helicopter with 8 rotors to provide the lift. The octocopters also have built in GPS and gyros to provide precise positioning control and stability. This provides an ideal platform to lift small HD video cameras. Octocopter kits are for sale at the German site Coptersale.
Below is a long video (over 15 minutes) of two fellows flying their octocopters over an old coke oven plant in Germany that has been converted to a museum. What is of interest in it is that there are shots where you can see one octocopter filming the other in operation.