For Everything Else, There's ElGamal

Downloading and installing GnuPG for Windows: 2 minutes

Downloading and installing the Enigmail plugin for Mozilla Thunderbird: 3 minutes

Generating a new 2048-bit ElGamal keypair and revocation cert in Thunderbird: 7 minutes

Automatically signing and verifying secure e-mail messages without all the extra steps it used to require: priceless