Inobtrusive lightweight Google Calendar alerter
Libnotify alarms are, usually, little windows that _receive no focus_ (thus do not take keyboard input away from other applications) yet are clearly visible even on a cluttered desktop.
SECURITY NOTE: this code uses python-gdata. The current Ubuntu version of that library, 1.2.4, will do the authentication in an encrypted fashion but the actual calendars will be transmitted in cleartext. If this is not what you want but instead prefer the whole exchange to occur over an encrypted channel, consider applying the patch found at http://groups.google.com/group/gdata-python-client-library-contributors/browse_thread/thread/48254170a6f6818a?pli=1
Also: getting 'thrown out' from Google Services is apparently normal, GCalert will reconnect automatically.