Fact is users spent a billion hours on the service in June, new research says. So be thankful, Mac users, that  a Facebook dev’s developing a desktop Mac client so you can keep an eye on your friend feed pretty much all the time…should be great for productivity. “According to Nielsen, the average Facebook visitor spent more than 4.5 hours on Facebook in June. That’s over an hour more than the average Yahoo user spent using Yahoo. Facebook says it has 200 million active users. That means users spent more than a billion hours clicking around the site in June,” reports Business Insider.

In order to promote the Facebook obsession, developers there are now building a Mac app that offers Desktop Notifications. This inhabits the menu bar at the top of your screen and lets you access your News Feed, recent Wall Posts, and messages. And it’s available now for download, though the company is warning that this is just a protoype. So don’t blame us if it goes wrong.

And for those Facebook users who like to send a minute-by-minute biography of themselves, the application features a universal hotkey for sending out a new status updates. We predict a lot of missed meetings and deadlines in the months ahead. You’ll find the client here. (Note: The page describing the app has since been update to specifically state Facebook are not developing this app, it’s an independent dev. Only just found out).