ranpwd uses /dev/random or /dev/urandom to generate cryptographically secure
passwords.  

Generated passwords may consist of any specified length and any combination of
upper- or lower-case alphanumeric characters or punctuation.  ranpwd can also
generate passwords consisting of hexadecimal, decimal, octal or binary numbers,
and format these as valid C constants for inclusion in source code.

WWW: http://freshmeat.net/projects/ranpwd