I password protected the directories of my WP install through the web host. I use my blog to record client interactions and information so employees and clients are the only ones I want even reading the title. This has worked for me for a while and people can’t even get the blog to show at all without a password.
I did it through my host’s control panel, so I can’t give you suggestions on how to go about it without a c-panel enabled web host.
Not sure if that helps, but we only need to log-in once at the beginning of the day.