The data port is the connector on the bottom. The same connector used for usb transfer on the computer. A data cable costs about 20 to 30 dollars and charges the ipod at the same time. I highly suggest the smart chargers that are about 30. Smart chargers condition the battery and prolong the battery life by a very large magin.
The mini jack is very poor. Listen to music with strong percussion or horns and you will hear a large percentage of distortion and clipping. I nearly sold the ipod after using it for a week due to this. I bought the data cable and was very pleased. The sound is still a little poorer than some other portable units I have used. The sony sounds incredible. But the ipod video is by far the most userfriendly and simply enjoyable to use. By the way. I may be wrong, but I believe the newer ipods can't replace the battery. If you have ever owned a cell phone and had the battery life deteriorate in under a year, then you understand the importance of a smart charger.