100 mutations seems high, and mutations make things harder to type. I'd rather add a 5th word (in fact, I do!) to get the complexity up where I want it.<p>I love the idea of including non-dictionary words, though. Numbers 0-999 gives you an easy thousand, any one of which should be easy to remember in a password. Proper nouns are also likely to be memorable, although remembering which spelling variation might be more trouble.<p>Also, if you speak a language other than English, that's another dictionary you can pull in (gaining a number of words dependant in part on your fluency...).