How do I revoke a PGP key?

gpg --list-keys
Find your key id:

pub   2048R/deadb33f 2012-03-10
uid                  Something <[email protected]>


gpg --edit-key 0xdeadb33f

Command> revuid
Really revoke this user ID? (y/N) y
Please select the reason for the revocation:
  0 = No reason specified
  4 = User ID is no longer valid
  Q = Cancel
(Probably you want to select 4 here)
Your decision? 4
gpg --keyserver keyserver.ubuntu.com -send-keys 0xdeadb33f

From the gnupg mailing list:

    gpg --keyserver pool.sks-keyservers.net -refresh-keys 0xdecafbad

now use gpg to revoke the UID

    gpg --edit-key 0xdecafbad

gpg displays a list of UIDs on the key. Enter the number of the UID you
wish to revoke. The list is redisplayed with an * next to the selected
one. now use the gpg command revuid to revoke:

    Command> revuid
    Really revoke this user ID? (y/N) y
    Please select the reason for the revocation:
      0 = No reason specified
      4 = User ID is no longer valid
      Q = Cancel
    (Probably you want to select 4 here)
    Your decision? 4

Answer the passphrase prompt and 'save' to update your keyring with the
modified key. Now send the key with revoked UID to the keyservers

    gpg --keyserver pool.sks-keyservers.net -send-keys 0xdecafbad