This is hardly going to be the biggest Facebook news of the day, but the company has made it a bit easier to stop getting notifications for long comment threads or very active groups. If you check your list of notifications, you'll see an "x" button when you hover over each one. Clicking that will give you the option to turn off any further notifications from the group, event, comment thread, or app. Previously, you could only turn off a set of notifications by changing your general settings or by clicking through to the thread in question, making this a nice, if incremental, change, especially for frequent users. Right now, it looks to be web-only; Facebook has said that the tweak is meant to "modernize the UI and add some features which will help users more easily consume and curate their notifications."