RegistryOfAccountsAndPasswords

How can we store our infrastructure account information?

The longer our projects goes on, the less we know what our other infrastructure team members are doing.

We don't currently have a secure registry of accounts and passwords - I would like is to figure out a way that we can do this so that we don't each have a list to lose, and that we can deputise new team members trivially.
* accounts, setup and howtos are needed - but how do we secure them?
* there is that FireGPG? addin for firefox i keep meaning to try out?