I use coil-less safety pins all the time when I knit. They make handy markers to help me judge distances and how much longer a piece needs to be. They are moveable motivators that help me to see just how much I knit in one sitting, especially helpful when the project is large and seemingly without an end. But I discovered when I combine the pins with numbered or alphabet beads that they become even more useful.
I also used the pins when quilting: they don't have exposed sharp ends like the speciality pins with arrows, and I can use my own codes. Numbers can easily mark rows. Letters are also helpful, and you are only limited by your imagination:
L = left
R = right
T = top
B = bottom