[IT] Pretty Good Privacy

Just learn this from my S'pore friend. Still excited with this because it is new for me. :D
readmore: http://www.gnupg.org/gph/en/manual.html#INTRO
http://pgp.mit.edu/faq.html

First we need to generate our own key:
gpg --gen-key
Then send the key to the mit keyserver (here my public key is 61837413)
gpg --keyserver pgp.mit.edu --send-keys 61837413

If you want to add signature to someone else key, first import their key from mit keyserver
gpg --keyserver pgp.mit.edu --recv-keys CFFFAD64
Then edit it
gpg --edit-key CFFFAD64
Afterwards, you will get some command prompt and type sign to sign, save to save, quit to quit. Give affirmative answer to the questions that need your agreement
>sign
>save
>quit

To Delete your own key from your local, first need to delete the secret key then delete the key. If you want to delete someone else's key, just do the delete key (2nd line below)
gpg --delete-secret-keys D47C263B
gpg --delete-key D47C263B

To get the list of key that saved on your local:
gpg --list-keys

To Search your key in the keyserver
http://pgp.mit.edu/