I love how when you use something from the gui that requires root, the key appears in the tray area and I don't have to reauthenticate while it's there. I think 5 minutes is too short however, and would like to be able to configure it as a number (rather than say a slider), with an option so that it never expires, and I have to manually give it up (good for days when i'm feeling lazy).
The pam_timestamp already supports timestamp_timeout option to set the timeout for the validity of the timestamp. However to be able to set it from gui it's necessary first to modify all services config in /etc/pam.d/ which use pam_timestamp to include one file with pam_timestamp in it which would be modified from the gui.
There is now common /etc/pam.d/config-util configuration file which allows you to set the pam_timestamp duration. After some discussions I've decided to not implement GUI interface for this. The functionality of the system wouldn't be improved much by this. So the bug is fixed - you are now able to configure the duration although only by editing the config-util file.