The U.S. Government would prefer that PGP not be available at all, and it is in fact illegal to export it from the US (except to Canada).

The politics surrounding PGP have lately gotten a little ugly, as evidenced by this letter from Phil Zimmerman's lawyer to the U.S. Customs department. (Zimmerman is the inventor of PGP).

Some more information about the history of PGP is available from this home page for Pretty Good Privacy. The home page also provides access to the program itself. If you are accessing this document from a site outside the US, please note that the primary link is to a site in the United Kingdom. Go for it.