The problem with Google Calendar is resolved (Feb 23, 2011, 11:30am)

Beginning around 6:00am, Google Calendar was experiencing problems Thursday morning (February 23). At 11:25am, Google reported that the issues had been resolved.

Find a log of the issue resolution from Google at http://www.google.com/appsstatus#rm=1&di=2&hl=en.

The Google Apps Dashboard --

For future reference, you can keep up with the current status of Google services (email, calendar, Sites, Docs, etc). at the Google Apps Dashboard