Clay Shirky has some good insites here: Many-to-Many: Why I Don’t Like Wikis Email
Weblogs provide a good counter-example. While wikis make a poor presentation medium (when my students use wikis, they universally and unconciously move the content into Word, PowerPoint, HTML or Flash when they ahve to present), weblogs are in many ways too pretty.
Every day I grieve the messyiness of email. I dont like it at all. It is not the plain textness of it but the html mess and the lack of a clear quoting protocol… one that was there in the early days. Then there is the whole line length issue, broken urls and so on. There is a loosing battle to keep emails in plain txt. I cant even find a decent email client. But Clay is onto something here… the mess is somehow convivial.