h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The writer missed the rod-busters, those folks who tie up re-bar to provide tensile strength to concrete structures. Bridges, columns, bond-beams, footings all owe their strength not to the concrete, but to the rods inside. This is similar to the use of steel tensioning cable.

Tie wire is nasty stuff, sure to slice and poke, Kleins are a brand and not necessarily a type. I can't recall if it was the wire or the re-bar that keeps your tetanus shots current.