I’m a big proponent of taking personal security measures when interacting on the internet. I sign all my emails using my PGP key so you know it is from me and not a virus, spammer, or a stolen account. I encrypt my netbook’s hard drive and keep a pretty tight firewall. For the most part I like to keep everything under lock and key because you just never know who might get your info and what they might do with it.
What if you don’t want to go through all this work. Without a Public/Private Key you can still use Symmetric Encryption to send files and emails and store data on your computer with an increased level of security. All possible with a few utilities found on most *nix systems.