iCal fail. With how often this happens to me (this time deleting a significant part of my upcoming calendar), you’d think that Apple would’ve introduced some sort of revision history for their syncing. I’m ready for something new.

I’m a big fan of services that can reliably keep my data in sync across multiple computers. Dropbox is likely my all-time favorite, and allows me to effortlessly sync 50 GB of documents, code, and media between my laptop and my desktop (ahem, .Mac). CoPress has a folder we’ve shared amongst the entire team for making accessible meeting notes, documentation, legal information, etc. Evernote, even with a mediocre user interface, enables me to quickly have access to my notes across any device. My notes are organized in the way of the GTD and I can easily search or filter by tag to get what I need.

Trust, however, is a very critical component of any relationship with a cloud or syncing service, and transparency is one method for achieving it. Dropbox is a pro in this regard; every account has at least 30 days of version history for anything that’s being synced.

Early yesterday, I made the move to Adium and decided that I finally wanted my Address Book accessible across multiple computers. Spanning Sync was the most obvious choice, as I’ve been using it to bring my calendar from iCal to Google Calendar and then to another iCal for several months now with no serious complaints. It’s blind trust in the service, though. Spanning Sync has a sync log, but the only way to revert to prior versions is to make your own backups and brute force it. The same thing applies to Address Book information which, in my situation, isn’t all that great of a solution.

I did as clean of a sync process as I could think of to get it right the first time. The Address Book on my MacBook has the gold master of my contacts, so I backed up and did a one-way sync to Google (overwriting all of my contact data) and then a one-way sync down to my desktop.

The result? I have 794 contacts on my MacBook, 743 contacts in Gmail, and 742 contacts on my iMac. It almost worked. Kinda.

Spanning Sync presents two significant issues for me that also affect the amount of trust I have in relationships with cloud syncing services in general. First and foremost, the numbers don’t add up. Not all of my contacts were synced properly, while some were entirely deleted along the way, and I have no way of figuring this out until I unsuccessfully try to find a person’s contact information. Of the 10 or so numbers marked as “favorites” on my phone, 4 lost their corresponding address cards. For the convenience of having contacts synced across computers, I’m willing to deal with this to some degree. Secondly, version history needs to be more robust than a log file. Every cloud service should keep a changelog of a week or more where the user can go back and revert an object to a prior state.

Intuitively addressing these issues in any web product means a greater amount of trust in the relationship.