Google Calendar is a Go
It is hellova slow at the moment, but it looks very cool...
Features:
-
Sharing events and calendars
You decide who can see
your calendar and which details they can view. Planning an event? You can
create invitations, send reminders and keep track of RSVPs right inside Google
Calendar. Organizations can promote events, too.
-
Staying on schedule
You can set up automatic event
reminders, including SMS notifications, and instantly bring up anything on
your calendar with the built-in search tool.
http://calendar.google.com/