After four years, Twitter, a social networking site that took microblogging to the next level, went through a surprising makeover that started in the U.S. yesterday. The new look and features promise to make the whole Twitter experience “faster, easier and richer”.

The new and improved Twitter will be rolled out in Canada in the future, though it’s unknown whether that means weeks or months from now. For the moment, many in the U.S. with Twitter accounts are logging on and finding a very different look and feel to the way information is presented on the site.

Since its inception, Twitter has always rained down tweets in a single centralized column that didn’t leave much room for anything else. The new layout now pushes that column to the left, while making room for a second column of equal size that will fill in the gaps on other pertinent information. This will include those who recently started following you, what they and their friends are tweeting and what some of the general topics are on the site as a whole. The left column will also do away with the “more” link at the bottom to roll out older tweets, instead just showing a long list of them continuously.

But more importantly, the right column will also be able to display embedded media, like photos and videos, so that you can browse and watch without having to navigate to a separate page. For example, if a friend tweets a YouTube link, that video will just appear in the right column, as opposed to opening a new tab to the YouTube site. In order to make this work even more, Twitter’s founders announced partnerships with 16 sites that include YouTube, Flickr, Justin.TV, Vimeo, yfrog, Plixi, UStream, Kickstarter and TwitPic. The details of these partnerships have yet to be unveiled, however.

Despite the considerable level of change, there are some elements missing that have been pointed out in the blogosphere. One of these is the way conversations are handled with multiple tweeters. A reply to a tweet will show up underneath, but the tree ends there. If someone has replied to that reply, it isn’t displayed to the other parties of the conversation. Third-party Twitter apps are able to do this, but no mention of it was made in yesterday’s announcement.

The general feeling among pundits is that Twitter is setting its sights on competing with Facebook for the social networking crown, particularly since the new features now open up more possibilities for app integration and advertising. Time will tell after the new look has finished its rollout.

Either way, there is a lot at stake. Twitter currently has 160 million users worldwide, and adds up to 370,000 every day. Up to 90 million tweets are posted on a daily basis as well. The sheer viral power of the site has already been proven, what with scandals, advertising campaigns and breaking news all crashing together over the last four years.