My wife’s iPhone, my iPhone and my daughters iPod Touch and an iPad are all sync’d together. I’ve done it by us all sharing the same iTunes account (mine) so if I buy an app or anything from iTunes it automatically gets pushed to all other devices and visa versa. You could prevent this buy going into the settings for each device and switch off the cloud and the syncing would be done via syncing over WiFi if you have this feature switched on, or when you plug the device into a computer via USB. It works seamlessly. The downsides are you get all the crummy music and apps that my wife downloads – I just delete off my phone, so not a huge issue. Most of my music is ripped from CD’s (i’m old fashioned like that – I still prefer buying CD’s) so for the music I want on my iPhone I set up a separate playlist for my music, and my wife has a separate playlist, so when we sync our devices we can customise the music that is synced by setting it to only sync selected playlists.
The other benefit is that things like contacts and calendar appointments are shared via the cloud, so I no longer have to keep on asking my wife when I can go out with the boys for a drink as I can see if the night is free via the calendar. The only other downside is that the iTunes account is tied to my credit card, and the wife can get a bit iTunes happy sometimes. Other than that it works a treat.
