I have worked in the cloud for a few years now. For me it all started with wikis. I used wikis for project collaboration and found them really useful at first. Eventually the wiki just ended up being a garage to store files in instead of a place for active collaboration. Obviously this wasn't the prescribed use of the wiki. If storage and remote access of files was the goal then my groups would have been much better off with another solution.
So we hit a wall and I couldn't quite figure out why, and then it clicked. Most of our meetings and efforts were done live, side by side with our teammates. While information, input, and ideas were shared vocally the finished diligence was being stored online in the wiki instead of transferring it between laptops on a flash drive. In a way this was useful and saved some time, but it wasn't by any stretch of the imagination a raving success. It wasn't until our teams expanded to include members from fifty to thousands of miles away that the beauty of the wiki was realized.
As our groups expanded, schedules clashed and it became difficult to sync up with the whole team. Enter the wiki and smoother sailing for our projects. Details of a project's progression now attended the drafts of documents. Being unable to make a call wasn't as disabling as before, it was saved in the wiki. We made revisions on the documents and worked as easily as if we were next to each other.
I'm not sure if being in close proximity to a team nullifies the usefulness of a wiki (right now I don't think so), but with remote teams, or at least a team that can't do everything together on the same schedule, wikis are a beautiful solution to project collaboration hiccups.