We need Plausible Deniability (i.e. What No TrueCrypt?)
Mostly good points but you should/can also throw TrueCrypt into the mix.
Apart allowing creation of a standard password based encrypted volume, one unique feature in TrueCrypt is the support for "Plausible Deniability". This is an encrypted volume with two passwords. One password provides access to the standard outer volume, and the other will decrypt a hidden volume inside the outer volume. Thus the user, if demanded his password under RIPA to decrypt the data, he simply gives up his outer volume password. By examining the encrypted data alone, even after decryption with the outer volume password, there should be no way for anyone to prove a hidden volume exists - hence he can plausibly deny existence of anything the authorities might be after.
This is not to say it's completely foolproof as it could still be compromised under certain circumstances.