Mount NTFS partition on-demand without password?

edit

Based on the answer from czerny, I have found out an (almost) perfect solution. The configuration file is placed in /etc, so that the changes are not overridden on next polkit update. Also I have restricted the right to mount any local partition to system administrators only.

Fedora 17 (GNOME 3.4)

1. Create the policy file

   $ sudo vim /etc/polkit-1/localauthority/50-local.d/99-mount-partitions.pkla

2. Put in the following content:

   [Password-less mounting of local partitions]
   Identity=unix-group:wheel
   Action=org.freedesktop.udisks2.filesystem-mount-system
   ResultAny=yes
   ResultInactive=yes
   ResultActive=yes
   

3. (Optional) The rights are currently elevated for anyone in the wheel group (system administrators). You can select only particular users e.g. this way:

   Identity=unix-user:lisa;unix-user:marge

   More documentation is at pklocalauthority.8.html.

4. Changes take effect immediately.

Fedora 18 (GNOME 3.6)

Follow the guide for Fedora 17, but the file should be saved to /etc/polkit-1/rules.d/99-mount-partitions.rules and its contents should be:

// Password-less mounting of local partitions
polkit.addRule(function(action, subject) {
    if (action.id == "org.freedesktop.udisks2.filesystem-mount-system" && subject.isInGroup("wheel")) {
       return polkit.Result.YES;
    }
});