This is an interesting idea! We know that many teachers find learning a new tool such as blogging to be a bit of a chore but most know how to email and add attachments so Posterous could be a great way to ease people into it! What I did to make this post was to send an email to this address - post@posterous.com - and attached some images, a sound file and a document to see how it would handle these. The results are this blog post!