I use a pair of PGP keys. One is a long term signing key, which I use to authenticate a shorter lived key for everyday use. The signing key is:
pub 4096R/4EC16D6B 2004-10-27
Key fingerprint = 3F69 2E64 6D92 3BBE E7AE 9258 5C0F 96E8 4EC1 6D6B
uid Jack Lloyd (Signing Key) <lloyd@randombit.net>
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v2.0.17 (GNU/Linux)
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Kp5vonFC67eDEfddWw==
=r26f
-----END PGP PUBLIC KEY BLOCK-----
The other keypair is set with an expiration date, and usually lives for about two years. This key pair is signed by my long term signing key. If you wish to send me encrypted mail, use this key. Currently this key is:
pub 2048R/8404914F 2011-04-21 [expires: 2013-04-20]
Key fingerprint = C01E 30FE B493 A6F2 14B6 16F5 9E5F FD7C 8404 914F
uid Jack Lloyd <lloyd@randombit.net>
sub 2048R/923D6648 2011-04-21 [expires: 2013-04-20]
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v2.0.17 (GNU/Linux)
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1eHznyLJxprmLw==
=tSo3
-----END PGP PUBLIC KEY BLOCK-----