I love these things! I use them for things not even sewing room related such as:
when I am making dog collars out of para-cord
holding pattern pieces together (such as lengthening and shortening)
clipping small pattern pieces so I don't lose them. (in place of a paper clip)
pin my braided ponytail to my shirt collar, when basting a quilt on the floor (when the gremlins steal my hair clip)
holding lace to ribbon in place to baste on what I am sewing