Some years ago I was working with Rhuarc on a project with lots of people from all around the world.
We used dotProject as management tool.

It is a great way to list all assets we need for the game (models, textures, sounds, functions) and assign them to team members. If someone leaves the team - and this will happen - we can see which assets are still open and needs to be assigned to someone else.

Together with subversion and other tools it would be possible to build the required infrastructure for an international online project.