We've long loved titanium bikes. Now we love titanium pens, too. These EDC scribblers (from $47) are light in your pocket, ultra-tough, and the machining is so precise that when the top is threaded, the joint completely disappears, making the pen look like a solid rod of titanium.
You can buy a three-inch version for your keychain or a full-size model. Both come with a replaceable ink cartridge and are available with a heat patina, decorative laser etching, or ruler design.