! isn't there supposed to be something about character set etc here??>
For the majority of people, the first question they ask with regards to file or email encryption is "What's the point? If I'm not doing anything wrong, then what do I have to hide?"
But a counter question is "Do you have to be doing something wrong in order to suffer from someone else's attention towards you?"
There are any number of various situations in which real harm could potentially come to you if the opinion or information you gave to one person were to be read by another. Some examples:
Most likely you can think of other situations where you would not appreciate what you are saying to become common knowledge to anyone other than the intended recipient. Part of the problem lies in the nature of internet and email communication. The internet route a message takes towards its destination can cross a dozen or more machines, any of which can copy and read that message. Likewise the message is stored and handled by a number of different mail handling machines before finally arriving at the destination.
A common analogy is the difference between sending a letter and sending a postcard. The postcard is open for any postman, mail handler, neighbour, to read. A letter, on the other hand, is safely enclosed inside it's envelope, and you will know if it has been opened and read (unless particular great expense has been applied to read it without your knowledge). When you send mail, do you always write everything on a postcard, or do you securely enclose your letter inside an envelope?
PGP encryption may be likened to placing your letter inside an envelope, safe from prying eyes, albeit an envelope with the strength of a safe.
But for me personally, I just like the idea of encryption because it's cool ;)