Using Facebook as your site authentication layer

I'm always kicking around ideas for various applications. One thing I look to off-load is user-authentication. Facebook has always caught my eye when I start thinking about that, but there's been something nagging at the back of my brain about offloading something as critical as allowing users to log-in to something that is centralized. It becomes your single point of failure.

Right now, I'm seeing that the unease was justified. Had an hour or so this morning before I started work that I was going to tinker with a small Facebook app I've been cooking up, but FB is completely on the fritz for all small apps. Imagine if that was powering my login mechanism...

Just another strike against centralized services like Facebook and Twitter.