Cleo Skribent Messograf Pen

Part multi-tool, part writing instrument, all German engineering. The Cleo Skribent Messograf Pen ($23) works great as a writing tool, accepting any Parker-style ballpoint or gel refills. But the chromium-plated brass body also serves as a metric screw thread scale, a tire tread depth scale, and as a 4-inch caliper that measures in both metric and inches. And not to worry, nervous pen-fiddlers — it still uses a standard click-to-open mechanism. [Scouted by Andrew]