Pom Pom Maker
Mine is from Lion. It was three concentric rings that snap together, so you can combine them indifferent ways to create different sizes and densities of poms. Also, there is a little bit of a ridge on the outside edge of the rings, which makes it really easy to cut only where you intend to.
I've used these a lot in the last few days on a sewing project I've been working on (more on that later). I'm not very good at sewing. Often, I 'forget' to remove the pins until I've sewed right up to that pin. If I sew over the pen, I may break the needle; to remove the pin by hand I need to lift the foot, which could misalign the (already misaligned--sh!!) seam. The tweezers were the perfect size and offered the right precision.
I can't cut straight lines in fabric without one. Since I am without one, I just can't sew straight lines in fabric, period.