You can add your country's FIFA World Cup 2010 fixtures to your Google Calendar by:

1. Clicking Add under Other Calendars on the left hand side
2. Select Browse Interesting Calendars
3. Select the Sports tab
4. Select Soccer
5. Select FIFA World Cup
6. Click Subscribe next to you preferred teams

If you want to add all fixtures then Ryan Cullen has done the hard work for you (http://blog.artesea.co.uk/2009/12/world-cup-2010-google-calendar.html) , you can click the + Google Callendar link at the bottom of his callendar to add it to yours.