Meograph is a free, easy multimedia storytelling tool. Students can quickly combine videos, audio, pictures, text, maps, timelines, and links to create what the developers call "four-dimensional storytelling." No registration is required and an education version is available. You have to play around with it to get the concept before introducing it to students.
This site is a nice alternative to other storyboard makers but my favorite hands down is Bitstrips.com The graphics are better and the price is good. You don't have to buy a year and just use it for the time you need it. Storyboard That, has an excellent yearly price and as stated above, a good alternative or different choice. It also may be easier to navigate and learn.
Our goal is to enable web users to create their own original animated video content for Free.
Memoov is developing a simple, fast and intuitive online Animation tools, supported by advanced server-side applications. This way we enable video creation flexibility like never before.