I have my Macbook Pro and iPhone 3GS synced via MobileMe, but want to add my old 2G iPhone into the mix, which i'll be running on Wi Fi. When I go to sync contacts, calendars and bookmarks, it says 'There are existing contacts synced with your Mac. Would you like to merge them with your MobileMe account?', then gives me the option to Merge or Not. My question is, if I merge, does it alter the data on my Mac and 3GS? In other words, does it push the old data on my 2G onto the cloud then onto my other devices, or pull the new data from the cloud to my 2G? Many thanks...