In the group I work in we make heavy use of email, of course, and we do have a few remote people who call in via VOIP to meetings, and sometimes we do screen sharing with them, but that's about as far as it goes. We rarely do video, though all our laptops have webcams. We do have a room with a fancy videoconferencing setup with cameras that focus on the person currently speaking -- it's very nice, but it can only connect to another setup of its kind, and the remote people on my team aren't in the one other location I know of that has such a setup; so it's not nearly as valuable as one would like.
The upshot is, I'm left agreeing with those who say that the most effective collaboration still requires being in the same place. Our remote people are certainly productive and part of the team, but we just don't have the same kind of impromptu conversations that I have with my podmates.
And I wonder what the solution might be. Double Robotics [0] certainly has an interesting take on that question; I don't know anyone who has tried it, though.