Wikis for Eduational Use

I seem to understand the idea of wikis a little bit better than I did blogs. However, maybe it is because I had some experience with blogs before reading about wikis. It appears to me that wikis would be an easier format for elementary students. There are topics already available for students to respond to instead of facing a blank page. For beginners, although not as original, this might be a much less frustrating way to get started. It also seems to me that once a student posted a writing, he/she would have a larger audience to read and respond to than would probably happen with a blog.
I think the benefits of using wikis with students would be that you are allowing students to use their technology skills to learn, communicate, and achieve in school as opposed to squelching their tech. skills as we normally do as educators. Also, the topics I found available at sites such as Wikiville looked relevant and of interest to students.
Some of the challenges of using wikis would be the numbers and limitations of the computers in our schools. Also the limited understanding of technology by some teachers who would be monitoring the learning would be a problem. I know I couldn't do it at this point.