I thought I felt a disturbance in the Force this morning. The source: Google. The search giant dropped an enormous bomb on me today: Sidewiki.

Sidewiki is a browser tool — it plugs in to Firefox or Internet Explorer (no Google Chrome support for a Google tool? How odd!). It allows you to write and read annotations to any Web site. Let me say that again: you can add content (or read content added by other people) to any site on the Web using this tool.

The additional information appears in a sidebar to the left of the body of the Web site (the tool shifts the rest of the site over to the right in a squished view). The data can include thoughts, comments and even active links to other Web sites. More on that later.

The only way you can read added material is to download the tool and activate it yourself while viewing a Web page. User-generated content won’t just pop up on the site on its own. But this tool could conceivably make a huge impact on the Web. Here are some things that entered into my mind once I learned of the tool:

• It provides users a way to comment on any Web page even if there’s no official comments section. This isn’t necessarily welcomed universally.
• On a related note, it could create a new space for flame wars. Don’t like a particular site’s message? Just pop open Sidewiki and make your thoughts known. Future visitors who enable Sidewiki will see read about your ire (assuming Google doesn’t remove the comment).
• It’s a way for experts to weigh in on subjects and provide a different perspective on issues.
• It’s a way to direct traffic from one Web site to another. This could turn out to be an enormous headache. How will sites prevent competitors from inserting links in the Sidewiki designed to siphon traffic away to another Web site?

Before you can use Sidewiki, you have to download and install the app into your Firefox or Internet Explorer browser. Your comments will be traceable back to your Google account, which might encourage people to act more responsibly than they would if comments were anonymous. Of course, nothing’s stopping you from creating a Google account just to troll another Web site.

Google says it will use an algorithm similar to the one it uses to rank search results to determine the most relevant and valuable additions to each Sidewiki page. Those comments will rise to the top of the pile of comments, burying everything else beneath them. That might help cut down on some of the trolling. But for sites that have very few comments, negative or insulting comments may still be visible.

Are site administrators going to freak out when they find out anyone can add or comment on the content of their Web pages? It’s possible. I suppose it depends upon how many people adopt the Sidewiki tool and actually use it. It may just be a flash in the pan. Or it could potentially change the Web landscape forever.

Google posted a video demonstration of the new tool:

Learn more about Google’s mission to organize the universe’s information at HowStuffWorks.com:

How Google Works
How the Googleplex Works
Why is the Google algorithm so important?