I knitted my first 5° Woolly in 2009. It's a way to avoid putting the heating on when it's a bit chilly but not absolutely brass monkeys. It's named after the difference in temperature inside and outside its woolly warmth.
We're lucky to live in a well insulated terrace house with double glazed windows but all the same winter is winter, fuel bills aren't cheap and we live in the UK.
In Britain when we were cold, we used to put another layer on, not whack up the central heating. Last year I had a friend to stay from warmer climes. She kept saying (pointlessly IMHO), "It's so cold! What's wrong with this country? We need the heating on." and I'd reply, "How about putting on a pair of socks and a jumper?" Cruel perhaps, but heating is not just about personal comfort, it's about carbon emissions, cost and conservation.
Anyway, this is my suggestion.
The plan is to use up stashes of knitting yarn that are sitting about all over the UK: your own, your gran's, your auntie's; you know it's out there. For the one in the photo, I used ten strands of different yarn at once, cast on 30 stitches and used 20mm needles, set off and waited to see what would happen.
When one ball ran out I just added another one, picked at random from the stash. That why the sleeve (left) is different from the body (right).
Benefits: warmth, energy-saving, using up the wool stash, learning a new skill, meeting knitters, making 5° Woollies for other people once you've got yours (and accompanying karma points), recognising other wearers and nodding in acknowledgement, owning a total, yet recognisable one-off, becoming a fully fledged member of the nice eco-people club.
I'll post the instructions if you like.
If you don't knit, here's your chance to start. I'm setting up my first 5° Woolly Club in Ealing, but I hope it'll go global.
Get in touch.