Interesting links

I found these interesting:

1. Kaprekar’s constant — not everything has to be useful to be appealing and fun.
2. Apparently the Roman Empire was more equal than the USA, while in Britain income inequality rose faster between 1975 and 2008 than in any other OECD member country.
3. How to get your keys back if you drop them down a drain.
4. Talking about big numbers…
5. The UK opens up NHS data, and the EU announces an ‘open by default‘ position for public sector information.