I'm sorry, pony BEAD lacing. It's what kids use to string pony beads on to make necklaces, etc. You can find it in the craft section next to the beads. It has a stretch to it and really grabs the wheel. You can also buy it from spinning places, but plan on spending about $8 for enough to string one wheel, or you can get it at a craft store for $1-$2 for enough to string a couple wheels.
It comes in a wide variety of colors too!