I commonly use the GnuPG OpenPGP client to sign and encrypt my email correspondence.

I currently maintain 2 public-private keys, one for personal use and the other for professional use. If you are looking for copies of either of my public keys, I actively maintain them on the usual network public keyservers. Their details are:

Personal Key

pub 1024D/EE7DC74E 2002-10-02
uid Conall O'Brien <conall@conall.net>
uid Conall O'Brien (Network Administrator) <conall@infocad.ie>
uid Conall O'Brien (Network Administrator) <conallob@maths.tcd.ie>
uid Conall O'Brien <conall@conall.obrien.name>
uid Conall O'Brien <conall@tcdcompsci.net>
uid Conall O'Brien <conall@obrien.name>
uid Conall O'Brien (SAGE-IE) <conall@ie.sage.org>
uid Conall O'Brien <conall@conallobrien.com>
uid Conall O'Brien (.Mac) <conallob@mac.com>
uid [jpeg image of size 5339]
uid Conall O'Brien <conallob@conallob.net>
sub 1024g/0E1CB4CA 2002-10-02

Professional Key

pub 1024D/603D4F54 2005-12-15
uid Conall O'Brien (IT Consultant) <conall@conall.ie>
uid Conall O'Brien (Asclepian Computing Solutions) <conall@asclepian.com>
uid Conall O'Brien (Asclepian Computing Solutions) <conall@asclepian.ie>
uid [jpeg image of size 5339]
sub 2048g/33F05B0D 2005-12-15

Key Signing

I'm more than happy to perform GPG keysigning with someone in the greater Dublin area. All that is required is a face to face meeting with me, and at least one official form of ID (valid drivers licence, passport, etc).