While we're on the subject, what are some good tools for receiving feedback, editing, and incorporating that feedback? Draft (http://draftin.com http://draftin

While we're on the subject, what are some good tools for receiving feedback, editing, and incorporating that feedback? Draft (http://draftin.com http://draftin.com) is pretty good for this, but not designed for larger scale projects like ebooks. Leanpub is awesome for distributing early / unfinished copies and opening the doors for feedback, but as far as I know, does not have any built in tools for collecting and integrating feedback or edits (gramatical, writing structure, etc). Any ideas?