If you ever do an auto-update on your WordPress site and instead of you site coming up in your browser window, you get “Briefly Unavailable for Scheduled Maintenance. Check back in a minute”, it can really freak you out. What happens is that WordPress slides in a temporary file called .maintenance until the core files and your database gets updated.
But sometimes it gets stuck and you get that message. But no worries, it’s an easy fix.
Just use an FTP on your server and get into your root installation and find that little bugger, then delete it. If for some reason it’s still stuck, it will ask you to update your database, click yes, and your site will return.