I’ve been a Plaxo user for a while now, but always seem to screw it up since there’s not a great way to sync between Plaxo and Mac Address Book or iCal. Plaxo has been promising Mac compatibility for a long time. I’m in the process of being a beta tester with them for a new product called “e2xo” that is Tiger-friendly. It installs a menu bar icon on your Mac which has the pull down option of syncing with Plaxo. I’ve synced seamlessly now between AB and Plaxo. iCall functionality is coming soon!
Mac users rejoice!