Although no one can agree on exactly when this started showing up on Facebook, pop-up windows appear when users hover over the names of friends, pages and places in their news feeds.

Hovering over the name of a friend results in a pop-up window that displays mutual friends, a friends button that enables users to change which groups that friend appears in, and a subscribe box that enables them to adjust their subscribe settings for that friend.

Hovering over Facebook pages for brands brings up a pop-up window with the number of likes for the page, as well as mutual friends who like that page.

And hovering over the pages for local businesses, results in a pop-up window featuring a map, the ability to get directions to the business, and mutual friends who like the business.

Facebook has not made any sort of official announcement about this specific type of pop-up window.

This feature parallels what happens when you click on an item in the ticker: a larger pop-up window opens to the left, showing the complete posting and accompanying thread.

Users: Are you seeing pop-up windows when you mouse over people’s names in your news feed?