StumbleUpon has redesigned its website and the changes are of more than passing interest.

The 'social discovery engine', which asks users to register things they like and then guides them at random through to related sites, unrolled the changes yesterday.

The alterations follow a rise in visibility for StumbleUpon. In July GigaOm reported that StumbleUpon was sending more traffic to American websites than Facebook. Its number of regular users doubled in 16 months, now totaling more than 20 million. It boasts 33 million monthly unique visitors.

So what exactly is different?

Visuals

The site has moved from the old blue, green and white logo, to a cleaner looking dark orange and white one. More importantly, the site as a whole is more visually focused. There are big, high-quality images to accompany each interest on a user's homepage and the toolbar is less obtrusive and cleaner (perhaps it owes some inspiration to the Hootsuite toolbar?). The difference in visual appeal is striking when you compare screenshots posted by GigaOm.

'Explore' box

What does journalism today have in common with the 1960s steel industry? Quite a lot, argued Dawn Williamson of Chartbeat, speaking today at "Les Nouvelles Pratiques du Journalisme" conference, hosted by the Ecole de journalisme de Sciences Po, Paris, in collaboration with Columbia Journalism School.

Before the 1960's the steel industry was dominated by big, inefficient, expensive steel plants. But then something changed. The industry was revolutionised by the introduction of "mini-mills" - smaller, cheaper, faster plants. Yet the big steel companies didn't want to adopt minimills, says Williamson. They were suspicious of the quality of their new competitors.

Today, Williamson argues, news sites like The Huffington Post, Gawker and Business Insider are the "mini mills of the journalism industry". Through a combination of news aggregation, blog hosting and user engagement, they're producing a journalism product that's faster and cheaper.

Are you ready to meet Siri's sister? No, not another shrill-voiced digital assistant, but in fact a new discovery engine, brought to you by Siri's sister company, Trapit. Like the iPhone 4S's voice command technology, Trap.it is the product of technologies developed in the CALO - Cognitive Assistant that Learns and Organizes - project. Trapit is now its own company and has begun raising funds, including seeking capital from Horizon Ventures, one the sponsors of Facebook, Spotify and Siri.

So Trapit has an impressive heritage, being descended from a $200 million artificial intelligence project, but what is it about Trapit that differentiates it from the ever-increasing amount of aggregators and discovery engines out there?

Conceptually it's not so different to Stumble Upon, a discovery engine that learns what you do and don't like. However, instead of flicking from page to page, Trapit simultaneously displays several panels related to different subjects- i.e. the trap - that the reader has said they are interested in or are likely to be interested in. When new information is found about those issues, Trapit updates the feed.

Advertising is crucial to the health of the news industry; it is the egg in the cake mixture, the crucial ingredient that binds everything together, even when print product sales are dropping. As the newspaper business navigates the transition to into the digital era, online advertising is becoming an ever more important revenue stream, much has been said about the necessity to 'stack those dimes' that trickle in from web ads in order to survive tough financial conditions.

In light of this situation, when someone proposes an alternative source of advertising, you can't blame news organisations for pricking up their ears and listening. What is this new source of ad revenue? The sponsored tweet.

'Great! Another way to grab some much needed cash!' you might think... but is it really a good idea for newspapers to issue sponsored material on their Twitter feeds?

Why could you argue that sponsored tweeting is a good idea?

1) MONEY. It's sad but true, newspapers need money. According to Nieman Lab, sponsored tweets can supposedly bring in $300 per day for a publication like The Statesman , which deals with news and entertainment in Austin, Texas. The publication puts out two clearly labelled sponsored tweets per day promoting local businesses and events. This is valuable revenue from 140 characters.