I'm working on a Cocoa GUI for FUSE (currently called MacFusion).
The idea is that it loads plugins for supported filesystems (working right now on SSHFS, NTFS-3G and FTPFS at first).
The plugins provide a configuration interface and code to mount/unmount. I'm hoping that this GUI will make FUSE goodness easily accessible to non-technical non-console people. In the future, it should be simple to support encfs, gmailfs, etc.
This will be a FOSS project once a first build is ready.
Anyone who wants to help is welcome, as are suggestions of any kind on the features/interface.