Back in April/May the IDPF had a contest to pick a new logo for Epub. they announced the new logo at their conference during the last week in May. FYI: I've given this logo the name "Enron Swastika" because that's what it looks like.
Just today I learned that some of the alternate logos were posted on a set of slides at the conference. I want to know which one you prefer. (Initially I was going to upload the pictures, but I think they look better on the PDF.)
I picked the official logo as the lead for this post. Here's my favorite: