The power of film

Although it's certainly up for interpretation, the message I took from Dziga Vertov's Man With a Movie Camera is that film can go anywhere and see anything. By covering the minutiae of a city (women riding in cars, the work of a single factory employee) and especially by superimposing images of the cameraman in physically impossible situations (i.e. a massive cameraman looming over the city, or a miniature cameraman inside a bubbling glass of champagne), Vertov shows the viewer that film has the power to observe anything.
But Vertov does not limit his message to shots by the cameraman-- he includes shots of the cameraman as well-- weaving through traffic, bathing in the ocean, balancing on the side of a moving car, but always holding onto his camera. In this way, Vertov conveys the ubiquity of film very cleverly. He not only shows the cameraman in a variety of situations (proving he can go anywhere), but implies the presence of an unknown, invisible, second presence (maybe the audience?) by the very fact that he has these shots of the cameraman.
Overall, I looked at Man With a Movie Camera as a fascinating examination of the nature of film and the interaction between the cameraman, his subjects, and his viewers.
Also, I loved the music; just had to get that in there.