When I have this one file that's really important for the big day ahead, I don't only save it on my USB thumbdrive (and backup USB drive), I email it to myself. That way, it's there- safe, guarded, untouched by the physical world, and hence, indestructible. (Even if I forget or lose my USB drive, I can retrieve the file anywhere as long as there's Wi-Fi.)
I don't claim to be the inventor of this technique, for I know many, many people who do this same thing. But why is it that every time I do it, I feel like I'm "going against the natural course" of my email account or I'm abusing a loophole or something. It's just that there appears to be no official designation to the task; there's no built-in menu that actually shows you it understands what you're doing; there's no special folder (unless you manually program it) for your precious files emailed to and by yourself; there's no confirmation that you've received that sacred file and that it is now well-secured in your inbox.
So as Ben Gibbard says, "I'm proposing a swift, orderly change." Attention Yahoo Mail and Google Mail: call it "mE-mail" or something, I don't know, but just do it...
-Leo Rafael L. Quesada, Entry #8