TrueCrypt

$ gpg --import TrueCrypt-Foundation-Public-Key.asc
gpg: directory `/home/stwn/.gnupg' created
gpg: new configuration file `/home/stwn/.gnupg/gpg.conf' created
gpg: WARNING: options in `/home/stwn/.gnupg/gpg.conf' are not yet active during this run
gpg: keyring `/home/stwn/.gnupg/secring.gpg' created
gpg: keyring `/home/stwn/.gnupg/pubring.gpg' created
gpg: /home/stwn/.gnupg/trustdb.gpg: trustdb created
gpg: key F0D6B1E0: public key "TrueCrypt Foundation <contact@truecrypt.org>" imported
gpg: Total number processed: 1
gpg:               imported: 1
gpg: no ultimately trusted keys found

$ gpg --verify truecrypt-6.0a-ubuntu-x86.tar.gz.sig truecrypt-6.0a-ubuntu-x86.tar.gz
gpg: Signature made Tue 15 Jul 2008 09:30:33 AM WIT using DSA key ID F0D6B1E0
gpg: Good signature from "TrueCrypt Foundation <contact@truecrypt.org>"
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: C5F4 BAC4 A7B2 2DB8 B8F8  5538 E3BA 73CA F0D6 B1E0

$ tar zxvf truecrypt-6.0a-ubuntu-x86.tar.gz
truecrypt-6.0a-setup-ubuntu-x86

$ sudo sh truecrypt-6.0a-setup-ubuntu-x86