Posterous - "The place to post everything. Just email us. Dead simple blog by email."
This is so fun! Instantly post anything on the web by sending an email. Attach files (many types, including .pdf, .html, .doc, .txt, image, video, mp3s) and that content will be embedded in your post. No need for membership, login, or anything! Just send an email and voila. The resulting post page has your own instant URL and lots of common blog features: the entry is dated, comments, subscription, tags, download links for the files you attached to your email, and more.
Here's a link to my own "prePosterous" first attempt, a quick email with attachments of a few file types. (I then signed up and created my own URL, but you do NOT have to do that!)