So I looked and looked for a way to get the Google Calendar to display within Project Pier and had no luck so I made this.
It's basically a copy of the Wiki plugin with all the controllers and names changed. Removed the do_textile function from the output and added html char decode instead of manipulating another function.
Since the code needs to display code properly, the original output didn't work because I needed to have the HTML be executed instead of htmlspecialchars used.
This function allows HTML to be displayed from the Calendar tab. It's super easy to use.
Download the code here: http://dustinalan.com/files/calendar.zip
Unzip the file to the plugin folder: ROOT/application/plugins/
Login to PP and go into the plugins.
Go to a project and click on the new Calendar tab
Add a page and put your iframe Google code into it - this way you can have multiple calendars if you want
And BAMB there's your Company's Google Calendar. Done.