We currently utilise a C program running on HPUX that after a set period of inactivity of a user logs them out, by invoking a single press of the F3 key every 30 seconds until the user is finally logged out. A warning message is displayed to the user telling them that unless they press a key they will be logged out. This process allows for a "graceful" exit from PROIV, rather than just killing the users session, thus avoiding any nasty DB integrity issues or unnceccesary rollbacks.
However we are moving to RHEL and the C program is neither compatible with RHEL nor can it be compiled on this platform.
Would just like to find out what you use to log users out after inactivity, especially if you are using Linux, RedHat or some other flavour.