Forcing actions at login

[Tim Chown]

I would like to know the neatest way of forcing certain actions to
be taken when a user logs in to the system.  For example, I would
like to ensure everyone sees the global message of the day, or 
perhaps get reniced if they're not a priority user on machine X.

Is the recommended way to simply put the name of a script in the
passwd file instead of /bin/csh (or whatever)?  I can't see any
other alternative as the user has to own .login, but are there
any ill side-effects from this action?

Tim