Power Favorites is a powerful bookmark manager for Windows which includes rich features. It supports online sync, posting bookmark to del.icio.us and organize bookmarks by tags.
feelDweb Online Alternatives
feelDweb Online is described as 'FeelDweb is an online social bookmark manager that allows you to organize webs and searches easily and visually. Has a community and private chat rooms' and is an website in the social & communications category. There are more than 10 alternatives to feelDweb Online, not only websites but also apps for a variety of platforms, including Mozilla Firefox, Windows, Google Chrome and Mac apps. The best feelDweb Online alternative is Diigo, which is free. Other great sites and apps similar to feelDweb Online are Advanced Bookmark Search, Vhumo, PasteDeck and Sitebar.