thank you, i was very imprecise!
it must be something very basic, but i just cannot figure out how the different users on our computer can all look at the same calender file of ical, make changes etc. so that we are all up to date on each other's schedule.
i tried to put it in the shared folder, but somehow the other users still look at their own calender file.

last night i discovered a new problem in this respect: i was hoping to link the palm m130 to the ical file. downloaded palm desktop installer mac421. but i cannot complete the installation. ("sorry the operation could not be completed due to a system error. (access denied.)")
Haven't tried it myself, but maybe you could make an alias in your own calendar folder to a calendar folder in the shared space.