A bag in which to keep your project, yarn, needles, etc. It can be a shopping bag or one specially made for knitting supplies. I tend to use a plastic bag to take around with me, but I also have other bags and baskets to keep all of my supplies. I got this cool knitting bag for Christmas.
It’s called the ArtBin Yarn Drum. You can get it for around $16 and it has a lot of nifty features.