Joshua Smart is organizing them again; he writes:

While advisors and committees are important, it can be incredibly helpful to discuss one’s work with peers in a lower-stakes environment, and it can be particularly enlightening to do so with those who take a different approach or have a different focus. Not only that, but there is evidence from psychological research that thinking about problems in relation to persons who are geographically distant can increase creativity. With students in programs from 8 countries and 20 different U.S. states, Virtual Dissertation Groups are a great (free!) way to capture some of these benefits.

The setup is simple: Students participate in three-membered groups, with one student each month sending a short-ish piece of writing to the other two for comments.

You can sign up to participate here. Open sign-ups go through Sunday, September 6th. (After that, spots are not guaranteed.)