Ask HN: how do you handle passwords in your startup?

Hi, I'm the cofounder of a startup and I start to worry about our password policy. Currently we share a protect file where all the passwords are stocked in clear. Everybody can access, every password and to keep everything sync we put it in the dropbox. I use keepass at home, but it's not perfect when multiple employees have to open it and modify it. So my question is : How do you manage your passwords and do you have differents users permissions levels ? I would love to hear how you deal with that in your startup. Thanks for your tips tl;dr : how do you deal with passwords and users permissions in your startup? EDIT: I'm of course talking about the password that we use everyday to manage the startup (gmail, twitter, google analytics,tumblr,...) not users' passwords.