I'm going round and round on a circular needle, with 100g of sock yarn. It's meditative and sort of slow, because you can't see it growing. Before you ask, it's that famous brand can't remember, in the colourway no idea.
I'm knitting a loooong tube - and will just keep going until I run out of yarn (I weighed things this morning, there was still 46g of yarn left in the ball). When I do run out, I'll graft the two ends of the tube together to make a soft and purpley cowl. Yum.