Indeed we should change our passwords regularly and thats why I rather use
your method.
That way I can keep my passwords with me withoud the need to store them.
Is kinda hard to change a password because I have 2 computers in my office
and my laptop so it is a pain in the ass to change a password because i would
have to save it somewhere, a usb or my owncloud server. And i don't really
feel comfortable doing any of those.
With your password generator is safer as even if someone would gain access to
my files there won't be a place where to look at for my passwords. So I can
change them constantly.