I wonder if you could send an empty envelope to yourself with certified mail, but not seal the envelope. Then when someone tries to patent something, you could copy their design, then put your drawings in your certified mail envelope, seal it and steal their design, claiming that you mailed the drawings to yourself months ago. Of course not having any other backup material or evidence of work will look a little fishy, but you never know. (Work is really slow today, so I'm just thinking out loud. Or silenty on the internet. Or something like that.)
Bob
