Fun sciency stuff
Optical illusions - Michael Bach's site with many fun and puzzling illusions
Project Implicit - test yourself for bias in a number of situations such as gender and race
Retraction Watch - what published material has been retracted or altered
Predatory journals - keep track of suspect journals and fraudulent material out there
Gapminder - play around with statistical data in a simple way
Wordle - create you own word clouds
Existential comics - philosophical comics
In Swedish
Bioresurs - material för biologiundervisning
Matteboken.se - repetera dina mattekunskaper från årskurs 3 till universitetet