Set Up As New Phone Question

[chaingang54]

Hello everyone, I've had an iPhone 4 Jailbroken on 4.1 for a while and I'm planning on updating to 4.2. People say it's better to set up your iPhone as a new phone. I have a question about that tho. When I set up as a new phone, will I lose all my items on iTunes (Music, Apps, Photos ect...) or will I just be able to sync it all up as usual?

[jonnyraincloud]

you set up as brand new, and re-transfer everything over

[thunderhawki]

...if you didn't do that initially --and you now want to do this-- how would one go about NOW setting up a new iphone? lol