No it is not. Without taking any secret information from the user not available/stored in the system itself there is no way to store a password on a system that is not trivially retrievable by someone who has access to the computer.
the OSX keychain encrypts passwords with your login password, and can be set to unload keys/passwords after a timeout, it is very much not stored as plain text.
Why would a non-technical user know that? Even if they could work it out if prompted to think about it, there's nothing to suggest to them that they ought to.
