If you’ve used StumbleUpon, then you know about their iFrame navigation toolbar that lets you rate sites that other people have stumbled without creating a StumbleUpon account. The tool is extremely useful for finding interesting sites and it also lets you comment on a site with friends. Facebook has embraced the iFrame functionality of StumbleUpon for shared items from your friends.

How does the new tool work exactly? Well I haven’t been able to test it out yet since none of my friends are actively sharing anything this minute but the idea is that when you click on one of your friends shared items, you will be taken directly to that page to comment on it. This also will help Facebook boost their pageviews significantly.

Imagine if half of the more than 140 million active users on Facebook clicked on a few shared items, each month. That would be a ton of traffic which would be marked for Facebook. With this small addition, Facebook has also duplicated a significant portion of the functionality provided by numerous news commenting toolbars and plugins that exist around the web.

If Facebook releases a more robust toolbar, users could instantly be commenting on all of the news articles they read around the web. Such a toolbar would also make it much easier for users to instantly share those articles with their friends. Given that MySpace released a toolbar in the past week, could we soon see Facebook release a competing (and more robust) toolbar?

Possibly. For now, there’s one easier way to share items on Facebook. I’m sure many users will find this to be useful. Check out Makinde Adeagbo’s blog post for more information.