A couple of days ago, just for fun I tried Posterous. I was impressed by the ease of use to get started. Just email your first post to email@example.com and follow up on the reply. It's very simple, but yet very sophisticated. I've no hassles with choosing a template, because there just are no templates and every post has a proper title.
Posting to Posterous is very simple, you either email you post to one of the many email addresses or use the excellent bookmarklet. Posterous also has various ways to automatically redistribute you posts to different microblogging, blogs, photo sharing sites etc., but I still need to figure this out in detail.
There is also a nice, a little hidden, function to import an existing blog. I was no effort at all to move my Tumblr log into Posterous. I had a few issues, but they were very quickly resolved by the Posterous staff, excellent service!
On top of this all, it comes with some basic analytics on page views and I've already had more referals from Posterous to my main blog here then I every had with Tumblr.
Tumblr, thank you... You served me well, but I move over to Posterous. The simplicity fits me better.