Bookmarker is a neat Mac OS X application for managing all sort of URLs (including file URLs). It supports import/export of XBEL (XML bookmark exchange language) files which are standard in the Linux world. It also supports sharing of bookmarks via Rendezvous or via the Internet.

Bookmarker hasn't been released officialy, yet - but it's used by a couple of testers since 2 years right now and so far all bugs have been squashed. If you're interested grab a recent version from the downloads section.