Connect

The Mindjet Connect service works well but is a bit expensive for collaborative hobby use ($10/person/month).

As a low budget alternative MindManager 8 also supports the use of files on a webdav server.

MindManager can not create maps on a WebDAV server but can open, lock, and save them. The most straightforward way I've found to do this is to paste the web address of the map in at the File, Open prompt:

http://connect.activityowner.com/develop/test.mmap