Many people heard of YouTube, how about TeacherTube? It looks very similar to YouTube except it was created by a lot of teachers. You can also upload the video for sharing and making comment. However, you need to declare the video is for teaching and learning purpose only and copyright free. It is more safe to view TeacherTube in classroom. Here is a video from TeacherTube. It is a quick look about a street in Nanjing, with the viewpoint from Western people. They descirbed this as a teaching material in school.