2 iPhones on same itunes?

[TSX]

When my wife get my 3g and she plugs it in how can i keep iTunes from syncing my contacts, ect to her phone? Will it know to keep the back-ups seperate?

 

[sammich]

In Address Book you can create groups of contacts. In the iPhone settings in iTunes, just select the group/s you want to sync for that phone.

 

[mavis]

When my wife get my 3g and she plugs it in how can i keep iTunes from syncing my contacts, ect to her phone? Will it know to keep the back-ups seperate?

As sammich described, you can specify which Address Book groups are synced. As for backups, iTunes keeps separate backups for each device based on the device's UDID. So no problem there, either.