Python programmer Chad Selph has developed a Google Chrome extension called OOptOut that lets you opt out of Facebook app permissions. This is particularly useful if you want to use a Facebook app, or website that requires one, but aren't comfortable with giving it access to your Facebook data.
When you install a Facebook app, the service tells you what the app is asking for: typically it wants access to some of the content you've uploaded to the social network, the ability to e-mail you, to post to Facebook as you, and/or to access your posts and data. Normally, you have to say yes to all of them, if you want to use the app in question, but this extension lets you pick and choose which ones you want to include.
When the app's authorization dialog pops up, OOptOut adds a small bar at the top with checkboxes for every permission the app requires. Once you're done picking, hit the Update button. The page will reload, and the app will then only ask for the permissions you chose. From there, you can hit the blue Allow button as you typically would.
Unsurprisingly, some apps break when using this plugin. This is because developers sometimes build their apps without the consideration that a Facebook permission might not have been granted: if they get a permission denied back from Facebook, the may not handle it gracefully. On the other hand, some apps may check which permissions you're missing and try to get you to re-authortize.
The app is not yet available on Google's Chrome Web Store, but it is available on GitHub. Unfortunately, this means that installing it takes five steps:
Do a git clone of this repository
Open up chrome to chrome://extensions
Turn on "Developer Mode"
Click "Load unpacked extension"
Find the folder of your git checkout!
Beyond getting into the Chrome Web Store, Selph has a few ideas for his extension, including improving the CSS, logo, and the name. He's also considering adding more detailed descriptions for each Facebook permission. He even mentioned possibly letting users add permissions the app isn't already asking for, though I'm not sure what the point of that would be.
I'll be keeping an eye on how this extension develops, including whether it is ported to other browsers. I've also contacted Facebook to see what the company thinks of the extension.