ftp://ftp.pgp.net/pub/pgp/utils/pine/
Using PGP with the Pine mailer.

• mkpgp2.1.tar.gz Version 2.1 of a script to integrate the Pine mailer with PGP. The author writes:

  mkpgp features: encryption (with or without signing), signing (with or without encryption), encrypted attachments selected via browser, effortless public key additions (from an alternate keyring, finger, lynx, or e-mail), decryption & signature verification, effortless encrypted attachment extraction, external editor of your choice, external spell checker of your choice, mixmaster remailer support and more.

• pinesign20 PINESIGN v2.0 by Robert A. Hayden
  According to the author, PINESIGN is a simple program that will allow you to automatically sign your email and news messages composed with the Pine 3.89 mail reader. It may also work with other mail and news programs, but it has not been tested.

• notes.3.92
  Version 3.92 of Pine is more PGP-friendly than earlier versions. No polished integration tools have been made available yet, but this file contains brief notes on how Pine v3.92 can call PGP, and gives example code.

• pinepgp10.tar.gz
  Despite the above claim, PinePGP is a series of Perl scripts that allow you to integrate PGP with version 3.92 of the PINE mail program.

• pine.html
  Aldo Valente has written a Perl script to integrate Pine and PGP. Read the documentation first!

Two pages purporting to describe the integration of Pine and PGP are available here and here