Buttons are probably an extreme example, and hopefully we have a few in our sewing kit. A nail can be used to simply punch holes, such as a heavy tarp or leather. To drill a needed hole ( such as in wood, bone or shell) the square shape of a horshoe nail gives a chisel edge. Peoples of the southwest actually used cactus needles. the sand is merely a abrasive, much like lapping compound. This is definitely a labor and time intensive method. Perhaps a small modeller's drill ( Im thinking of the impact ratcheting version) is worth inclusion in a larger gearkit? As to T-REX I must beg off. I had the distastefull duty of shooting a dangerous coyote today. My Dine' friend has to rebalance me with the universe :O(