Storyboard and Lesson Builder tools.
PBS Learning Media's Storyboard tool allows you to create a collection of videos, text, and images organized around almost any topic of your choosing. The collection appears in a collage-like format. You can share your Storyboards directly with your students through the PBS Learning Media website (you have to create an account in order to do this). Storyboards can also be created by students. As a teacher you can assign topics to your students and have them develop storyboards around their assigned topics. When they have completed their assignments students can share their Storyboards with you through PBS Learning Media.
PBS Learning Media's Lesson Builder tool is similar to their Storyboard tool. The difference is that in the Lesson Builder you can include quiz questions for students to answer after watching a video that you have selected for them.
Applications for Education
Both the Storyboard and Lesson Builder tools could be good for creating short introductory lessons to larger units of study that students are undertaking in your classroom. The shortcoming of both tools is that you are limited to content that is hosted by PBS Learning Media.