Just found Xtranormal on Twitter (from @NikPeachey) and made this movie in about 30 minutes with their "text to movie" feature. The movies are very simple to make which is good for younger students, but don't have a ton of options like Photostory. Xtranormal reminds me of a more complex voki and it is free, for now. It could be an interesting way to put instructions for students on a website or wiki. I tried it on my class wiki here.
By the way, Twitter is so great for finding these kinds of tools. I am following about 90 people on my personal account, mostly educators, so there are lots opportunities to hear what people are doing in their classrooms. And, since twitter is only 140 characters, people are much more likely to share ideas they might not otherwise blog about. I think I get more ideas from Twitter than just about any other resource.