Bookmark2 - Bookmarks2 is a powerful productivity tool that makes is much easier for anyone to save their links...
Firefox Sync - Bring your Firefox bookmarks, tabs, or passwords wherever you go with Firefox Sync. Share between computers and mobile devices. Get Firefox now!
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
LinkLocker - LinkLocker is a lightweight bookmarking service with an emphasis on privacy.
Linkman - Linkman Pro allows for managing large amount of URLs in its own database.
Sitebar - SiteBar is an Online Bookmark Manager.