Restoring an iPhone from another phones backup?

[Nickel020]

I got a 2nd iPhone 3G and now I'm trying to get all my contacts and other data from the first one to the new one.
Itunes only lets me restore the new phone with the sync of the new phone but not that of the old one. Can anybody tell me how to "clone" the data off the old phone onto the new phone? Do they need the same software version for this to work?

Thanks!

[Miro89]

if u want the data on the old one to be on the new one then they have to be running the same firmware to do that so u can restore via itunes with the backup you have