I arrived back in the UK a couple of days ago, and seem to have brought an unwelcome stow-away in the form of a norovirus. I’m on the mend now, but since my brain still isn’t functioning well enough for any real work, I thought I’d catch up on the emails I missed while I was away. One was a reminder that the Flu Survey is up and running again for the year. It’s a citizen science project from the London School of Hygiene and Tropical Medicine that tracks trends in flu across Europe. If you want to help, all you have to do is register on the site and report any flu symptoms weekly throughout the winter. The organisers are hoping for a lot more participants this year and are even having some prize draws to encourage people to get involved. So here’s some citizen science that’s so easy you can even help from your sickbed, should you be unfortunate enough to be stuck there for a few days.