Omnivorous Surfer

Even if you keep them organized, if you've collected bookmarks over a long period of time you will possibly have some duplicates and probably have several that no longer work. AM-DeadLink is FREE software (Windows only), recommended by Kim Komando, which will find duplicates in your browser bookmarks and text files. You can then verify and delete them. It works with IE, Firefox, Opera, Chrome, HTML, and URLs from tab- or comma-delimited files.

As a bonus, you can also download FavIcons for your IE or Opera Favorites.