If you pay any attention at all to typography, layout, type faces, fonts, leading, kerning, tracking and the like, and have ended up amassing a collection of type faces from the famous designers and font foundries, you'll end up needing some method of organization. The type face or font organizers that come with operating systems are basic, so vendors have channeled some Gutenberg and come up with replacements.
Despite its once-poor reputation, I have been using Plaxo to keep my iCal and Exchange calendar sync'ed as well as a way to keep in touch with business contacts. I've been syncing using the Plaxo Outlook client on an old clunker of a Windows box at work, to go Outlook to Plaxo, and also using the Plaxo iCal client on Mac OS X, to go iCal to Plaxo. It also works to sync Address Book entries. My goal in using it was to be able to use the Mail and iCal software in OS X, and not MS Entourage. I dislike Entourage because it puts your mail, calendar and address items in a single large monolithic database. Hard to back that up, and, it gets really, really large after a while.