Poco

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 <a href="http://notions.okuda.ca/wordpress-plugins/google-calendar-widget/" rel="nofollow ugc">http://notions.okuda.ca/wordpress-plugins/google-calendar-widget/</a>

Google Calendar Widget

This plugin installs a sidebar widget that can show the upcoming events from a Google Calendar feed.

stoutdesign

The Stout Google Calendar plugin allows you to easily add and customize embedded Google Calendars to your WordPress site. You can even change color settings that are not normally modifiable, allowing you to seamlessly integrate Google Calendars into the look of your site. No more ugly Google Calendars!
Features include:
<ul>
<li>Customize the color scheme of embedded Google Calendars</li>
<li>Options from the Google Embeddable Calendar Helper can be modified directly within the WordPress Admin</li>
<li>Save multiple calendars, each with it’s own color scheme, size and display settings</li>
<li>Display calendars in a Widget, Pages or Posts via shortcode or in templates</li>
<li>Live preview of all changes to a calendar as you make each change</li>
<li>Easy color picker or directly input hexadecimal color values</li>
</ul>

Stout Google Calendar

Stout Google Calendar allows you to add and customize the colors and options of embedded Google Calendars directly within the WordPress admin.

Google Calendar Widget vs Stout Google Calendar