Today I tried out icalx.com and it seems to work perfectly with Apple iCal 2.0.3. You can publish your calendar from one computer and subscribe (read-only) from other computers and you can view your calendar in any webbrowser (read-only).
To overcome the read-only limitation in this setup I also subscribed to Google Calendar, but the interaction is tedious. (I can add calendar items to the google calendar and subscribe to the google calendar in iCal from the other computers, but they are still totally separate calendars. I can then manually cut-copy-paste each individual google calendar entry into my iCal calendar using Apple iCal, but this is rather inconvenient and error prone.)
Anyway, if you create new events on one machine most of the time and simply want to review them from other machines this is perfect (since all automatic).
However, I still think I have to set up my own server to get all the functionality I want. Year 2006, and we are still in the stone-age of the computer era. ;-)