The D180 Folding Pen | Superior Titanium Products, Inc.
A flat-packed foldable pen that follows you everywhere! - Yanko Design
Foldable Pen w/ Nail Cutter – Purple Tag Gifts Co.
Amazon.com : 2 Pack - Retractable Pen Reel for Thick Markers & Carpenter Pencils - Carabiner Clip for Apron, Belt Loop or Bag Strap - Great Gift for Baristas, by Reel-N-Rite (Black) :
A Minimal, Durable, Retractable Pen - Yanko Design