I don't but boy do I wish I did! I have a couple of baskets for balls of yarn, a folder/container/bag thing that I keep all of my needles and knitting tools in, a shelf I keep all of my knitting books on, a bag I keep all of my ribbons, fabric, tulle, etc. in, and everything else (glue guns, needle and thread, etc) is in various drawers around the house. I sure could use a room for all of my craft supplies! Lol.
I don't have one but it would be nice to have a place to organize my yarn, patterns, hooks, etc. I think I would do more sewing if I had somewhere to set up my sewing machine and cut out patterns w/o having to put everything away all the time.