Empty cleaning wipe container turns into a fab yarn holder
Well, given that I was just telling you about my new crochet habit, I think Tracy's hack is perfectly timed:
I often knit up baby blankets and booties and was always frustrated with my yarn getting unwound. So, decided to re-use an old disinfecting wipes container (cleaned out really well first, or course). Just pop off the top and put your yarn in and use the already built-in "yarn guide."
Depending on the size of the project you're doing and needle length, you may even be able to fit your project right inside the container too. If your yarn balls are skinny enough you can fit them into the narrower disinfecting containers... this makes them easy to use in the car, as they fit nicely inside your cup holder and you can easily knit on the way to Grandma's :)
...assuming someone else is driving!
Related: Knitting Pretty