This other day I was reading http://pgp.sourceforge.net/pgpFAQ.php which is an FAQ (Frequently Asked Questions) about an encryption program called PGP (Pretty Good Privacy) which is still one of the standards in personal file and email encryption.

But I thought this part was interesting:
Q: Why should I encrypt my mail? I’m not doing anything illegal!

A: You should encrypt your e-mail for the same reason that you don’t write all of your correspondence on the back of a post card. E-mail is actually far less secure than the postal system. With the post office, your mail is handled by postal workers. Take a look at the header area of any e-mail message that you receive and you will see that it has passed through a number of nodes on its way to you. Every one of these nodes presents the opportunity for snooping, as do all systems that can listen in on the communication between these nodes. Encryption in no way implies illegal activity. It is simply intended to keep personal thoughts personal.

Xenon puts it like this:
Crime? If you are not a politician, research scientist, investor, CEO, lawyer, celebrity, libertarian in a repressive
society, investor, or person having too much fun, and you do not send e-mail about your private sex life, financial/
political/legal/scientific plans, or gossip then maybe you don’t need PGP, but at least realize that privacy has nothing
to do with crime and is in fact what keeps the world from falling apart. Besides, PGP is FUN. You never had a secret
decoder ring? Boo!
–Xenon <an48138@anon.penet.fi>(Copyright 1993, Xenon)

Now I’ll admit for the average person, PGP might be considered a little bit of overkill. But Xenon does have a point about the average person should use encryption. I have a free clone of PGP and then I also have Thawte personal email certificates (http://www.thawte.com/secure-email/web-of-trust-wot/index.html) which utilizes the same process for verifying the certificate is valid as going to your banks website.

Now for Instant Messenger, there are encryption add-ons for AIM.  There is also Bitwise or Skype which are both encrypted by default.