As a former Palm OS user, I was accustom to syncing my Palm device with both my Mac and PC. My primary interest with this cross sync is to get the same contact and calendar information on all three devices. This is a path that can be wrought with disaster since none of these devices have exactly the same fields. For my Palm devices, I used third party apps to deal with these differences. Pocket Mirror on the PC and Missing Sync on the Mac. They did a very good job and I almost never had to worry about data getting messed up or deleted.

Cross syncing with the iPhone is a different experience, it reminds me of the early days of the Palm. Syncing the iPhone on both Windows and MacOS is done via iTunes. iTunes does not expect a iPhone to sync calendars and contacts with different computers so it puts a extra dialog telling you this and asking if you want to replace or merge the data. This is an annoying extra step. The Windows iTunes interface is exactly the same as the Mac, including the sync dialogs.

The iPhone's calendar application is lacking in many ways. It does not duplicate iCal exactly, it's missing categories, it doesn't display attendees and the alarms are not persistent like they are the palm (they alarm once and that's it). Syncing with Outlook in a exchange environment has been safe so far the several times I have synced. iTunes has not wiped out categories or attendees or any meetings. I have noticed if I delete a individual appointment in a repeating event, it does not get removed from the iPhone. I'm suspecting that the iPhone stores categories and attendee information but it's not shown in the calendar interface.

Syncing the phone with the Mac, after syncing with outlook, results in a single category in iCal called "Outlook Calendar". if the iPhone does remember the categories and attendees, it doesn't transfer them back into iCal. For that reason I'm not syncing the iPhone with my Mac, Outlook wins in this case.

Syncing contacts works a lot better. The iphone contacts application (if you can call it that, it's actually located in the Phone application) does know groups, which is the equivalent of categories in Outlook. I first synced my contacts with my Mac, the with Outlook and there were no contacts missing or screwed up. When I synced back to the Mac and used the Check For Duplicates function in found lots of duplicates, I told it to merge them and I couldn't find any missing information. I think that category information might be lost with the sync but the contact entry is kept. The Mac's address book is kind of weird in the way it displays groups, so it might have the same contact under a group and not assigned to a group. I need to experiment with this a little more to understand what's going on. Since it's not loosing information I will continue to sync contacts and use the merge duplicates feature in Address Book.app.

This is my first look at cross syncing. I haven't researched it beyond my early attempts here. I can live without the calendar information on my Mac for now. I need contacts on all three systems. This cross syncing is working for me at the moment even if it's imperfect. It's no where near as good as it was on the Palm. I hope that either Apple improves the syncing experience or, more likely, a third party will step and take over the syncing.