A friend of mine has iPhone 3gs he synced the iPhone on a laptop, now that laptop is not with him, if he syncs the iPhone on another system will he loose all his data (contacts, apps, music, messages, video, emails etc), is there a way to backup all this.

Also he is on 3.1 and he intends to format the phone, will he be able to back up all his data, then format the iphone, JB and reload all the old data on the phone?