Times are changing. Kathy Sierra features a timeline on her blog which suggests that the 1970s and 80s were about how well we could learn, the 1990s and 2000s focused on how fast and how much we could learn, whilst today's education should be based on how much we can unlearn. And, she says, learning to let go of old and out of date rules is one of the skills we all need to develop. Futurologist Jack Uldrich is applying the same principle to the medical profession, arguing that the key to unlearning is to come to the realisation that 'we are all in a fog', and can't clearly see the future. Unlearning will be a strategy for coping with rapid change and uncertainties, he argues.

App of the week Denso Free, from the Apple App Store Denso is a couch potato's dream. It is an easy way to discover and organise interesting Web videos. It works like Instapaper, except that instead of saving text, you are saving videos for future viewing. Sadly, the app will not work with YouTube videos, but it works with many other sources. It has compiled a list of videos to help you find topics that interest you. You can also watch, share and comment on videos shared by your friends on Facebook and Twitter. This is a universal app for both the iPhone and iPad but, as with most apps which handle video, it looks best on the iPad. Perhaps the best thing about this app is that it was made in Singapore.