Foxmarks is one of the best Firefox extensions out there. Foxmarks lets you create a profile at Foxmarks.com and syncs your bookmarks across any number of Firefox browsers on various computers you use.
This means you can seamlessly bookmark in one computer at work and come home to find it and go to the site you want. In fact, you can even create different profiles for work, home, etc and see just those bookmarks depending on where you are.
Foxmarks is now available for Internet Explorer as well as Safari. But, it does not offer password syncing in IE & Safari, just bookmarks. And if you used your own server to store bookmarks & passwords with Foxmarks, you can’t do that either in IE/Safari.
iPhone users get sync for Mac Safari.
I tried this out in Internet Explorer and found it to work seamlessly!