The "Flipped Classroom" involves the use of video or podcasting in the place of direct instruction (usually accessed as homework), which allows students to get class time to work with their teacher on individual projects, practical experiments or assigned problems. It is not about replacing teachers with screens, but is meant to increase personalised contact time and interaction. Here are some resources you may be able to use to incorporate "flipping" in your classrooms:
The Khan Academy is a massive collection of over 2,600 instructional videos (screencasts) from algebra to finance to physics. This site also has 220 practise exercises so students can "learn what they want, when they want" at their own pace. Personally, I think they are a bit boring, but many thousands of students have found them useful for study and revision.
Twig Science Films has over 500 outstanding short films about science topics, categorised as Biology, Chemistry, Physics and Earth Sciences. "What is an atom?" "What is sound?" "Time Travel" and "How the Oceans Formed" are just some of the free films with lessopn plans and aligned to (UK) standards.
Teacher Tube is a site for student and teacher-created videos, safe for school use. I have uploaded videos here, including dissection demonstrations and verbal descriptions of the structure and function of the digestive system and human eye, for later use.
Although YouTube is blocked at many schools, most students can access this site from home and some have probably uploaded their own videos here. There are some great educational videos here, despite the many questionable offerings. The CSIRO have their own channel, with some excellent videos uploaded, including "Capturing Solar Energy in Gas" and "Pollen under the Microscope." "Nature By Numbers" is one of my favourite YouTube videos, but then again, I am a nerd.
Podomatic is a free site where you can upload and share audio recordings. You can use free audio recorders such as "Audacity" or apps on iDevices such as "Voice Recorder" to record your podcast and then upload it to the site.