Multiuser Problems


I have an iMac G5 running Tiger and 3 people use the computer. I want each person to have their own desktop and files, but I want to share our music and picture libraries, calendars and contacts. So far I have worked out the iTunes and iPhoto problems, but I haven't been able to find a workable method for AddressBook and iCal. I do not have a .Mac account, which I assume would be the easiest solution.

Any ideas?