Google Calendar Widget free WordPress plugin

This plugin installs a widget for showing a Google Calendar agenda on the sidebar.
Once installed it adds a sidebar widget called ‘Google Calendar’ that may be dragged into your sidebar.
Each widget can be configured with a ID of the calendar feed, a title, and the number of agenda items to show.

The calendar feed ID is the ID next to ‘Calendar ID:’ in the Google Calendar settings.

Multiple widgets can be used on the same page and each one can reference a different feed.

See also http://notions.okuda.ca/wordpress-plugins/google-calendar-widget/