iphone to 3g transfer issue?

[SweepeR]

guys ima swtich from my iphone to iphone 3g and I was wondering how can I get my contacts list, pics, txts, etc into the new iphone? For example, u know when u go into itunes and u synce it puts all ur contacts and txts and w/e that was on it on ur phone, would I do that with the iphone 3g or i lose everything?

Cuz ima put another #/line on my old iphone and was wondering what will happen wiht my contacts on the old one?

and once i do transfer this, how can i completely remove my contacts list and all that for the new line user?