As you can imagine, it is difficult to work with people who live, literally, across the globe. Even those in the same country were far way. However, we used several forms of communication to collaborate.
Primarily, we used a forum where everybody could see each others posts, allowing for a merging of ideas, like a giant mixing pot. If anyone had an idea, they could simply post it, and others would come and discuss about it. This was the preferred way of communication. Sometimes, we would use email, if we were personally addressing one member.
Occasionally, we would set up a three way phone call, where ideas could be shared, and real-time feedback could be given on all aspects of the site. Not only were these phone calls productive, but they were enjoyable and light-hearted; it added a human element to the project, after working so long with so many machines.