C-Slide webcam covers came about by accident. The creator, Ron Gustaveson, developed it as a promotional product for company branding at trade shows. But when people kept coming back for more, he figured the C-Slide webcam cover was a product in its own right.
The C-Slide attaches to your computer with two-sided adhesive strips. Once in place, you move the cover right or left to open and close it. It measures about 6 inches by 3.3 inches and is only 0.1 inches thick. That's thin enough so that you can close almost any laptop with the C-Slide still in place It costs $15 for a family pack of three and $5.95 for just one.