It's not uncommon for Websites today to let visitors post comments; typically, however, they have to register first. Pushnote, on the other hand, is a new browser plug-in that lets Web surfers post uncensored comments on any site across the Web, whether or not that site enables comments itself.

"It makes the entire Web one big, democratic comment platform," in the site's own words.

Once users download the free Pushnote plug-in--which is now in beta--a dedicated browser button turns green when the user visits a page where people have left comments through the service. That same button turns red, meanwhile, when there are new comments from friends on any site across the Web. Users can follow the comments of their friends, and they can also reply to friends' comments across the Web.

By displaying the highest-rated comments and the most discussed pages across the Web, Pushnote is designed to highlight the most interesting developments on the Internet as they happen, without demanding that users search for it. The service can also cross-post to Twitter and Facebook. Mobile versions are coming soon.

No Editing or Deleting

So, that's all the good news -- particularly for socially oriented consumers. Though Safari and Opera users are not yet included, support for those browsers may well be on the way

For businesses, Pushnote's implications aren't yet entirely clear. One fairly significant downside is that comments made with the service apparently can't be edited or deleted in the current version, which is bad news for any company that's been unfairly reviewed or criticized by a Pushnote user. It's actually a problem for finger-tied typists, too--if you make a typo, there's currently no way to correct it. I wouldn't be surprised if this aspect changes in not too long.

I should also note that to even see Pushnote comments, businesses will have to download the plug-in themselves.

Pushnote clearly removes a significant degree of control from the hands of companies large and small--after all, they can no longer moderate, edit or remove comments true or untrue left about their companies on any site across the Web, including their own--not to mention potentially removing comments-generating traffic to their own sites, which could have a whole world of separate revenue implications.

Nevertheless, it seems to me there could be opportunities here as well.

Business Opportunities

It should be noted that we've already seen similar capabilities in the form of Google's SideWiki service, which hasn't exactly been an overwhelming success. Assuming this new tool begins to get some traction, however, I believe companies of all sizes should:

1. Join Pushnote. If you don't download the plug-in, you'll never see what people are saying about your company and your products or services, even on top of your own site.

2. Incorporate Pushnote in your monitoring of social media . You already keep tabs on the comments made elsewhere on the Web--this could very well be an important one to add. And don't just monitor--take users' comments seriously and respond quickly and appropriately, as always.

3. Participate in Pushnote conversations about your company and its products, just as you do elsewhere on the Web. View this as another opportunity to engage and interact.

5. Embrace Transparency. Pushnote is one more example of the openness and transparency that's increasingly being required of companies today. There really is nowhere left to hide--every company's best and worst features alike are inevitably laid open for all the world to see online. Embrace this transparency, and you can triumph from it, in the terminology of Trendwatching.com -- which, incidentally, considers customer reviews "the new advertising." Run from that transparency, on the other hand, and suffer the consequences.

I'm no mystic, but I have a good feeling about Pushnote. Smart businesses would do well to begin considering how they can make the best of it.

Follow Katherine Noyes on Twitter: @Noyesk.