Lucid natively supports both iPhone and iPod Touch 1G, 2G, 3G, 3GS and 4G models (iPad should also work) running up to firmware 4.0.1 without the need to jailbreak. This is due to GNOME 2.30 libimobiledevice support. For a video demo see this
youtube video. For the iPhone4 (iOS 4.1), music syncing does NOT work as libgpod has not implemented this yet. You can view the iPhone filesystem by using ifuse.
If you have a password set up on your device, unlock it first before connecting the USB cable, otherwise Ubuntu will not recognize it.
USB Tethering is not supported out of the box, but you can make it work by following
this guide
iPod 5G Nano: After making sure libimobiledevice is installed (and possibly reinstalling it if necessary) you may need to re-install the network-manager package in order to be able to read and write properly.