Over the years I have tried several solutions for syncing my contacts between different accounts. Even back in the days of Palm Pilot Desktop for Mac, ActiveSync, Intellisync, and my personal favorite, The Missing Sync. In the long run, they never ended up working for me. Each of them usually ends up creating duplicate records. So I have made quite a mess of my contacts many times over.
What a fantastic guide, really detailed and to the point. Very helpful.