So the latest social network, in fact the best social network since Facebook, is now Pinterest. Barely a day goes by without a top headline story from the likes of LinkedIn and Mashable promoting the increasing take up of Pinterest.

I’ve been using Pinterest for a few weeks now. Since then it’s been interesting to see more people joining and following my ‘boards’. It’s principally the same group of early adopters who keep signing up to the latest new social websites in search of the next big Facebook.

Pinterest is a super-simple concept. If you see something interesting on the web, you ‘Pin’ that content to Pinterest, which inserts a good looking graphic from the interesting page on to a virtual cork board.

In the past, this type of site was called a bookmarking site and would have competed with Digg, Delicious and a thousand other startups which have been acquired by the big .coms (and then spun out again).

Pinterest seems to make bookmarking interesting again through a few simple new concepts:

• Grouping ‘Pins’ together as interest groups
• Keeping it simply to Pin items to Pinterest
• Adopting the ‘following’ principle of social networks

It’s the user interface that’s the knock out factor. There are some key aspects of the site that sets Pinterest apart from other sites, and we’ll start seeing the usability features on other sites.

One of these features is how the site horizontally scales so well. At home I have a large widescreen monitor. I can easily fit a browser window next to a Word window, and Skype or Yammer around those. Looking at Facebook when a browser window is maximised looks ridiculous – a thin sliver of content among a wide, white page. However Pinterest constantly fills the entire screen, adding more content as the browser window expands vertically and horizontally.

There’s no doubting that Pinterest has been growing very, very quickly. The site is still very fast at loading and rendering, despite most of it’s content being graphics.

I don’t think Pinterest is the killer app for bookmarks.

I still use Delicious, mainly because I’ve been using it for several years and have hundreds of bookmarks, but also because most of my links are stored because the content was interesting, not just a graphic on a page.

And I still use Flickr for all my images because BT gave me a Pro account with my broadband package and it stores the graphics in such high resolution.

If I see an interesting graphic on a page, such as an infographic, I typically put it on Twitter and if I need to find it again, I’ll search my tweets.

As for Pinterest, I’m not that sure where it fits in. Most of the boards seem to centre around fashion and food. So maybe Pinterest will end up as a niche site for these industries. Until the next big social network comes along.