The 4th largest international sporting event in the world kicked off this week in New Zealand. The Rugby World Cup is surpassed in scale only by the soccer World Cup, the Summer Olympics and the Tour de France. Due to New Zealand's time zones, rugby fans all over the world may be relying on the Web to keep up with the action. Given that ReadWriteWeb was founded in New Zealand, it behooves us to provide you with all the details!

In this post we tell you how to monitor the Rugby World Cup online, using a range of impressive official websites and social media accounts.

As you'd expect, the event has an official website that is constantly updated with news and results. You'll also find the fixture list, tickets information and much more.

The official site is also a good place to check out video coverage of the games, with full match coverage available on past games. Note that there is a 72 hour delay in the USA, presumably due to TV rights. Although in our tests, none of the videos seemed to work in the US. So your mileage may vary. Here's a screenshot of what it looks like, in case you can't see the videos right now:

For further video content, the RWC YouTube channel offers a daily 5-6 minute news round-up. Below is the latest one at time of writing.

The RWC Facebook Page has 1.3 million 'likes' so far and is a good place to discuss the games with other fans. There are currently over 300 comments on the South Africa vs. Wales match.

Rugby fans may also want to check out the extra features in the Facebook Page menu, including separate pages for Discussions and Events.

The official Twitter account has nearly 75,000 followers at this stage. It's an active account, with helpful updates and even match scores. The official hashtag is #rwc2011. In addition, you can follow Twitter lists for teams and players.

For a flavor of the atmosphere around New Zealand as the RWC plays out, check out the official Flickr account.

There are a number of RWC mobile apps available, including for iPhone/iPad, Android phones, Blackberry and more.

Finally, if you'd like a calendar of the games for Google Calendar, Outlook and more, local rugby fan Mike Riversdale has created a few options.

Overall, the online coverage of the Rugby World Cup is comprehensive and makes excellent use of social media. Other than some issues with watching video from the U.S. and perhaps other countries, the online presence for RWC2011 is more than satisfactory.

As the founder of ReadWriteWeb and the company's only kiwi (I live and work from New Zealand), I can't resist finishing this round-up by stating: GO THE ALL BLACKS! It's about time we lifted the World Cup again, it's only been 24 years :)