PasswordMaker works a bit like that, although in a much more lightweight way, making a hash of the site's domain name + the master password you enter each time.

PasswordMaker works a bit like that, although in a much more lightweight way, making a hash of the site's domain name + the master password you enter each time. The downside is that it doesn't easily work everywhere due to stupid rules like "your password must/must-not contain punctuation". http://passwordmaker.org/ http://passwordmaker.org/