45. Post-It Note
Year Invented: 1968
Designer: Art Fry/Spencer Silver
While attempting to develop a super-strong adhesive, Dr. Spenser Silver accidently created something that was pretty much the complete opposite—an adhesive that could be applied, removed, and applied again, without damage to the object it was applied to. He attempted to market the "low tack" adhesive to 3M to no avail. In 1974, Art Fry overheard Silver talking about his invention and quickly realized a use for the tack; he applied it to paper and created the Post-It Note.