Yesterday I received an invitation to join Pownce, a new social networking site that allows users to post mini-blogs easily. I already am a member of Twitter which does basically the same thing. The biggest difference, and one that will be of use to teachers, is the ability to attach files to postings. This would be a great tool for teachers to post homework assignments with any worksheets or handouts needed to complete the assignment.
Won't websites do the same thing? Yes but you have to login to your website or boot the software, make your changes, save your work, then post it on the Internet. With Pownce, a teacher can have the site open on their web browser. When they need to post something, they just type it in, add any attachments, then click the send button. Students can view postings on the site directly or can subscribe using RSS news feeders. Teachers can also post any changes to an assignment just as easy.
Pownce is still in beta and users can join by invitation but when they open up to everyone, I will let you know.