Subtitled "Rewire the Web with your point of view," Trailfire allows you to mark pages with annotations that can be either plain text or HTML (including dropped in widgets like those from YouTube or Google). The next time you mark a page with the same trail name, the pages are linked together in a trail.
Its creators claim that there are "far-reaching implications towards creating a user generated meta-web, a Social Web." According to the site:
Trailfire runs a blog called Occam's Machete ("Given two equally predictive theories, hack the stupid one to a pulp.") on which they've posted some early applications of the technology. Here's a screenshot of a trail at work:Trailfire is a hosted service that enables anyone to comment on any web page. Place a 'trail mark' on a page with your comments or notes. A trail mark can contain text, images, videos and other media types. When you give several marks the same 'trail name' you are forming your own navigation path on the web. We call this a 'Trail'.Anyone with a compatible browser can follow a trail. To make a trail, you will need a plugin to your browser. Learn more.Making trails is easy. Trails can be used for hundreds of reasons, ranging from serious research to serious fun. Use trails to organize and annotate web pages or to communicate your point of view. Share your trails by sending them via email, posting them on your blog or by publishing them on Trailfire.com. Learn more.
There are some interesting BtoB implications here, as this seems to be a much more user-friendly and on-the-go version of Squidoo, Seth Godin's brainchild that encourages a network of various experts to post their "lenses" on topics.