Calendar collusion complexity

Simson Garfinkel disusses the emerging standard iCalendar in the latest version of TechReview. While this may go some way in exchanging data between calendars, I fear that calendar standardization and exchange is still some way off – chiefly because of lack of functionality on the client side. Our requirements are simply, still, too complex for the software.
The chief problems lie with weak handling of privacy rules, especially when the user of the calendar crosses domains. For example: I use calendar software, and work for two organizations that also use it – the Norwegian School of Management, and the Concours Group. I also have a family life, with wife and children that demand calendar coordination. Being able to synchronize all this would be simply wonderful – but the functionality is not there yet.
For example: At the school, we share our Lotus Notes calendars – except I don’t because I don’t want my private activities to be broadcast to all and sundry. Notes does not support a default setting where an outside user could only see the time, not the content of an entry. That would mean that for every entry I put in, I would have to change the privacy setting manually – so I don’t bother. My calendar is therefore closed to outsiders, and and people who want to know whether I am available will have to call my secretary. If it was possible to set default “private” – so that outsiders could see what time I was busy but not what I was doing – I would share my calendar in an instant.
A further problem comes when you cross domains – for instance, I would like to have a calendar where I could have a setting of “Concours” (where Concours people could see both time and content, others only “Concours business”), “NSM” (ditto for my academic colleagues) and “family” (guess what). I realize I can do that for a single calendar client – but sharing the settings reliably across clients and networks is just not possible.
A third aspect is that time zones tend to be badly implemented in between-calendar standards (if not in all clients), and since I work in many different time zones, I frequently run the risk of misunderstanding timing for teleconferences and such.
The solution, of course, is constant vigilance and a great secretary. And constant search for a calendar client where the depth of the software matches the complexity of the life of the intellectual mercenary.