July 25, 2008 (MacWorld) Synchronization is hard. It may sound simple: copy personal information, such as contacts and events, between computers and keep them all up to date. But over the years, we've seen sync programs that don't quite work. I not-so-fondly remember manually deleting hundreds of duplicate contacts from my Palm handheld years ago, and even now, I run into records in which separate companies and individuals were long ago squished together into the same contact.

Apple Inc. has thrown resources at this problem over time, and the latest incarnation, MobileMe, adds the capability to synchronize some data to devices and other Macs lickety-split, the way Microsoft's Exchange Server performs in the corporate world. In fact, Apple calls MobileMe "Exchange for the rest of us." MobileMe definitely comes closer to fulfilling the promise made by the six-year-old .Mac (which it replaced), though it has more than a few rough edges.

With an online service such as MobileMe, I'm writing about a moving target shortly after what turned out to be a disastrous introduction. Not only was MobileMe rolled out at the same time as the iPhone 3G and the iPhone 2.0 software update -- which greatly strained Apple's overwhelmed servers during the first days -- the service also ran into snags days before that when it was soft-launched in advance of its grand debut.

The service was frequently unavailable, and synchronization often didn't work properly. Apple apologized for the snafus and extended all MobileMe subscriptions by 30 days. So, it's possible that the reliability of the service will improve over time.

Getting MobileMe

Existing .Mac subscribers automatically became MobileMe subscribers, and were given a new yourname@me.com e-mail address. New accounts are available from Apple for $99 per year ($149 for a family pack of five licenses), but you can also buy a boxed version that includes a registration code from retailers like Amazon.com Inc. for less.

Upgrading the software on the Mac is oddly tricky, however. Under Leopard, the Mac OS X Update for MobileMe 1.1 doesn't appear in Software Update. You must first open the .Mac pane in System Preferences, and after a minute or so, a dialog appears informing you of the update. Only then does Software Update make it available. According to Apple, this unusual two-step process was required to add the MobileMe imagery to the preference pane; future updates will be available just via Software Update.

Users running Tiger won't see a MobileMe update at all, even though the service works under Mac OS X 10.4.11 (except for Back to My Mac and some sync options, which are Leopard-only features). Although I didn't run into any problems with syncing under Tiger, several reports in Apple's discussion forums advise deleting .Mac preference files if you encounter problems. (In the Finder, go to [home]/Library/Preferences and look for files with "com.apple.dotmac" in the names.)

I recommend making a backup copy of your Address Book and iCal (or Entourage) data before upgrading, just to be safe. To avoid initial data munges, it's a good idea to also use the Reset Sync Data option in the Preference pane.