TypePad Micro: In addition to being able to blog via email, iPhone app, "Blog It" bookmarklet and the general WYSIWYG dashboard, this tool also allows users to cross post to Twitter, Friendfeed and Facebook. My only complaint with TypePad is that there are only 2 design themes to choose from. For someone like me with very little design sense, it's a long process to find something right. As well, if you'd like to add another blog or add new design themes you are required to pay for a monthly subscription service.
Tumblr: This service offers users publishing via iPhone app, desktop widget, the Tumblr bookmarklet, text message, email, AIM and even via audio call-in. Tumblr's theme gallery offers hundreds of options for design. Users can also add their posts to Facebook and Twitter via the free customization. Tumblr allows users to create more than one blog and add more than one contributor for free; however, all edits show up in the same dashboard in chronological order. This means you may have to dig to revise an older post.
Posterous: Posterous is the original email publishing microblog. Users can email posts, publish them via the web editor or upload them from the PicPosterous iPhone app. The service allows users to set up auto posting to Facebook, Twitter, Flickr, Picasa, YouTube, Vimeo, Tumblr, Blogger, Wordpress and Xanga. You can also choose to post to just one service in addition to your Posterous account by emailing firstname.lastname@example.org to specify Flickr or email@example.com to post to Twitter. Of the three services, Posterous offers an advantage in its ease-of-use and while it's lacked design abilities in the past, the company recently launched themes and theme import from Tumblr.