I love the practical use of Rollyo. It would give students direction when completing an assignment for a teacher. Instead of aimlessly searching the Internet, they will be able to focus on only the websites that you trust and that are relevant to their report, project, etc..
The only thing I didn't like about Rollyo is that it is really slow. I used Internet Explore and I would still have to get up and finish some chores while the pages were loading. I found that the earlier you go on Rollyo, the faster it is. Not sure why this is so. Anyway, I created a Rollyo on Native Americans. I would think this would be a good topic for fourth or fifth graders. There are a lot of erroneous website concerning Native Americans so I am glad I was able to pick out reliable ones. Here is the link