Most encryption algorithms (including block ciphers) can be used as a hashing algorithm for passwords.

Just encrypt a common known plaintext string and use the password as the encryption key. This is exactly how various hashing schemes like UNIX's crypt() (based on DES) work.

Knowing the plaintext (e.g. a set of NUL bytes) is useless as long as the encryption scheme doesn't have a weakness against known-plaintext attacks [EDIT] that allow you to recover the encryption key somehow.