I use GNU Privacy Guard, which is GPLed and implements RFC 2440 (OpenPGP).
Here's my public key; you can also download my key as a text file.
-----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG v1.2.0 (GNU/Linux) mQGiBDzdHT8RBAD1mluWWE2yzThEddT2uwyH2UkeIax1o/RpVUgJXvm4298rwjKm cg+mFF/pQAkIpRFP+OC2JGCL8IFaPm/s43qcnbBjnRRsz9bmDHzUeQlq7804azlx DYth6lc7TwVkeGOeoLVzlKGTGOM/vYFT+KdLp35/3lrUCZoeGJMQxLCwwwCglGh8 CfYqyOZTLmFt1CVcOJNoqt8EAIMSUBCEfDCgBHFoNVMKm/WhVDczUR25J8Lrmarp 47cc3k3mcs49zSycpOG0M5hx/eZad8LCezedEtFuzW948GWxJkbI6hoitGmc8rj+ yWSbp0PS+iji+1R03gwDxz1l9SwSEZ+J4MTCSdBfC8zCs5cD9i/gsZe7njU3vWIw 1BLKBAC5keaIwZI9OpmjCiQjCGybnOF589DFbinJvWz5xNJ6j/iQ6Du4UGfGQ9BH cXiv8pWrcB2CcRcZqxzzZVBWFhZRW580ZCeC0YGbo+hThhUuOhfG7Id0HjYcBuBO VTjALVZVL0q1s3YS6yj7pCS5LFeciBuq9fsteqrs+nEt0QWcaLQkSm9obiBIYXJy aXNvbiAoQW90ZWEpIDxqb2huQGEzMi5uZXQ+iFcEExECABcFAjzdHT8FCwcKAwQD FQMCAxYCAQIXgAAKCRA/RmkxPxK+I8ltAJwJpePjndK5Mv/xv2bhVWlbI5yfXQCd F85vEky45Ds6TAuyMt93VM5lp9e5AQ0EPN0dQhAEAI9KaMrUJMa42HYB3nnG/Foa rzqmQGH9M0939xn+mUXF+3VFcvhLboHo4bRyo570Z7wRYRE/VeZekFdgcsPjY7Qc Q8ATApVj9CnvpD38mAgXHfnkd5bHyYm9fC9kD1+APky3RQYa9UGKF8O7JCkj+suq eyMmZearg+bgvDYKENpfAAMFA/9cTH/ZhQVJAKPihyDfZ3U/N8Yoe7VhSwC94WM8 J+c1ByndD5csJvARrzJ1AwdxD6NNsugMEDKXN6fjXtmPzuqbviPWL7ZXrqsOFU1p Ouw4UDDpZDKyCxyiIebvA0tkypEvXV/jSLmewC/xsE4jLC6G1c56lK9nW9lGY/yv PbsrOIhGBBgRAgAGBQI83R1CAAoJED9GaTE/Er4jQ3cAn2NyMGLewVuopRrN/nbp IlhYKrRwAJ0VUwtv5grAWnbmvn8MhNCTCwqlNQ== =KB3w -----END PGP PUBLIC KEY BLOCK-----