On a recent visit to my sister in law, we noticed that she had a magnetic knife rack. I was slightly worried about knives falling off. However, having tried hanging some really heavy things from the bar, I was convinced it was safe.
You just need to drill a couple of small holes in the wall and fix the metal backing plate. The magnetic part just clips over the mounting bar. It comes in several different lengths, so you can choose one that fits your available space. Obviously, you can also use it for things like graters and scissors that are made from steel. A great way to reduce the clutter in your kitchen drawers, making extra space to fill with even more clutter:)