The is a free bookmark export tool similar to the one that comes with IE but with some very nice features.
The feature I find most beneficial is the ability to create drop down lists.
My brother recently wanted to show me some pictures of his sons baseball team on the Internet. The problem is he couldn't remember the URL. Even when he found the site hosting the pictures he couldn't locate what he was looking for. If he exported the bookmarks to a web site he could have navigated right to it.
Many times you don't want to share company internal bookmarks. Favorites Plus is a nice way for you to seperate it out.
There are other ways to achieve the same results using social bookmarking sites such as site bar.
Here is a list from WikiPedia : http://en.wikipedia.org/wiki/Social_bookmarking