One of the main missions of an educator is guiding students through instruction.  When a technology comes along that helps with this process I get excited.  Screencasts are recordings of a computer screen output and by using screen casting software I can record the click by click actions of my own computer and share them with my students and guide them through a website or highlight how to use a particular program like Photoshop or Windows Live Movie Maker.  Screen casts have become a powerful tool to help keep students on track and provided step by step instructions for those who may have fallen behind during initial in class instruction.  Because a screen cast can be played again and again as many times as a student needs, students can work more independently with technology.  The YouTube video attachments produced by Screencast Central gives you a great guided tour of what a screencast is by actually showing you a screencast of a screencast.  While the redundancy may set your head spinning, the straight forward presentation really helps to clearly show what a screencast is and the possibilities that this technology can bring to the classroom.