Innovation in paper is something that is welcomed in the PDF community. The work of physicist Kate Stone is combining conductive inks with paper to create interactive documents.
The pieces of ordinary paper have interactive electronics printed onto them. The combination of touch sensitive ink technology and printed circuits create cost effective products. Think dynamic newspapers that can play audio, link to video and pair with headphones.
Electronics in (or rather on) the paper can be synced using Bluetooth and wireless creating paper that can respond in real time.
This could have a range of applications for PDF. Ideas are already buzzing around some PDF communities. The waves of innovation will almost certainly come. Innovation from the tech and software industries will take the pioneering technology that has been created, and remix, redefine and repurpose it in new and exciting ways. This could have far reaching effects for all fields.
A TED video of Kate Stone demonstrating the almost magical paper being used as a drum-kit, DJ decks, interactive newspaper and poster that changes in real time can be viewed at the Ted.com website.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.