picture-4Twitter is a very natural extension of commenting on blog posts or video — and in some ways it’s better than a link stuck on a specific website or page, since it has the benefit of publicizing those pages through tweets.

A German company called SumtnSumtn hopes to capitalize on that by integrating Twitter into a bookmarklet that travels with you wherever you browse. When you pull it up, it hovers over the page, lets you comment on a specific website and share a link to your comment via Twitter. The key feature is that it lets you find other people who have done the same.

SumtnSumtn says it could make a few business models work: It could have content-specific ads in the bookmarklet; sell a premium, ad-free version; or work with content providers to create their own branded bookmarklets.

A few other companies are moving in on the same idea. Disqus (the comments system used by VentureBeat) integrated Twitter back in May, while another service, UK-based Chirrup, fetches comments from Twitter and sends the author a feed. The difference with SumtnSumtn is that the author doesn’t have to install any kind of plug-in. It’s up to the user if they want to tweet about a page.

The concept could be pretty useful if executed correctly. Commenters can find others with similar interests and build a more tight-knit community around a Web site, which would be useful for targeted advertising. However, SumtnSumtn doesn’t seem to pick up comments made through other clients like TweetDeck or Tweetie — a factor that could hinder its growth. I would be surprised if a bigger commenting service like Disqus doesn’t incorporate similar functionality.

The Hagen, Germany-based company is self-funded.