EtherPad Alternatives

I was talking w/an English teacher last week about Etherpad and did a demo w/my yearbook kids. Great tool, but going away, right?
Fortunately, I put a call out for help to my Twitter peeps and got a number of responses w/alternatives:
http://typewith.me/
http://www.ietherpad.com/
http://primarypad.com/
http://piratepad.net/
Also told about a Wikipedia article w/more options: http://en.wikipedia.org/wiki/EtherPad#Clones @ptruchon send me the Wikipedia article mentioned above, but it has changed (not for the better) since sending it.  He suggests this substitute: http://doc.etherpad.org/etherpadsites.

Gotta love Twitter!

More to add?  Lesson ideas for using it?