Yes. Tyranicus connected his iPhone to my iPod charging cable in my car, and I used his iPhone cable for my iPod. They are all USB-30pin Dock Connector cables... they are all compatible.
Just be careful about firewire cables. I had always heard that the 1st gen nano dropped firewire support, but then i read recently that it was just the latest gen nano that dropped the support. I have no idea about iPhone's support for firewire