The Calendar Hype ??

Google released the Google Calendar this week in itz stint to build an online empire. Slashdot has referenced some online calendar applications and I browsed this one called Kiko. Kiko seems to have been built using Ajax with all the "feather touch" UI. The question I have in mind is "Do we really need an online calendar ?". Are we not commiting a privacy suicide if we punch in all our schedules online ? Alrite even if we trust the Security of all the online calendar applications, are we sure that if someday DOJ will not ask Google or Kiko or Yahoo to submit all your schedules to them ?