SimilarWeb is a firefox addon and web service that lets you discover similar web pages when browsing web. It appears as an icon on your browser that expands to the sidebar displaying content similar to a page you’re currently at.

You can also customize the way similar content is presented in the sidebar by choosing between different view options like thumbnails, small icons and the list view. Finally, users can vote recommended web pages up or down, filter similar sites by tags, and even suggest a site.

See SimilarWeb demo video:

Features:

• Similar sites finder.
• Currently works with Firefox only (IE coming soon).
• Customize the way similar websites are presented.
• Rate recommended sites and suggest a site.

Check Out SimilarWeb @ www.similarweb.com