To check the signature run:
  echo | gpg
  gpg --auto-key-locate keyserver --keyserver-options auto-key-retrieve parallel-20130522.tar.bz2.sig

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)

iEYEABECAAYFAlGb9g4ACgkQLGIp4v////E7KwCeKsGZXdGtrvWmTa7hmX1YxlN0
JFQAnjR+wMPYrrxsKW4UqEPrTcm3BI8w
=Lm3T
-----END PGP SIGNATURE-----