Fun On Friday #149: Passwords

I've been thinking about passwords. In particular, how can I help eleven year-olds to choose secure passwords that they won't have forgotten a week later?

Thanks to a suggestion from Mr Jones, I was tempted to go for the xkcd approach:

Password Strength - xkcd
...but I think may be too abstract for younger children.

Mr McSwan suggested Dinopass. Child friendly and "good enough" security for now... as long as I remember to revisit password security every year as they get older and discuss how they can make them even better.

Do you have a fun password utility/site you can recommend?