Is there such a thing as "open" double-blind peer review? Is there such a thing as "open" double-blind reviewing, where the author's comments, the reviews, and any interchange between author and reviewer are viewable, not just by the editor but also by the other reviewers, but completely anonymous?

If so, what are some journals that have this practice?
Yes, there is such a thing as "open double-blind" reviewing: the "Frontiers in" journal series uses exactly this model.

During the review process, "control" is handed back and forth between editors, reviewers, and authors in an incremental "conversation" model, in which the paper might go through many incremental revisions.  If the editor determines the paper cannot proceed or an author is unable to reply to reviewer comments, then it is rejected.  Otherwise, reviewers, once satisfied with the paper, sign off with an endorsement.  When all reviewers have endorsed, the paper proceeds to publication and the identity of the reviewers is revealed on the final published version.