Apple's .Mac service has introduced ".Mac Bookmarks":
- Take your bookmarks with you wherever you go. With new .Mac Bookmarks, a handy surfer window with your favorite bookmarks opens on any Internet-connected computer, providing instant access to your favorite places on the web. Use it on your home or work computer, even at an Internet cafe.
Safari 1.0 and iSync 1.1 are required to sync your bookmarks. The service provides a Web Window interface which is accessible by Mac or PC (or presumably, any web-browser).