Yesterday and today, I wrote a chunky patch for gvfs to allow it to use the "house arrest" protocol for iOS devices. This is the protocol is rather more well-known as "iTunes documents sharing".
You can see a tedious example of how you can use it in this Apple KB.
For GNOME, we did it slightly differently, and you don't need to use your music manager as a file manager for your non-music device. Plug the device in, and all the apps that support file sharing will be showing up in a "Applications on Foo" device, on your desktop.
Managing files with a file manager, what a brilliant idea.