I'm in need of an external hdd. I need to get all my stuff off my pc (tons of mp3, lots of pics, that type of thing) and onto an external drive so that I can reformat the pc hdd so I can give that pc to my son. Basically what I need to know is can I buy a drive, plug into my pc, dump everything on it, then immediately plug into my mac and read/write from the external drive? I have no idea what the file format is for a mac. I do know I'm able to read off my pc hdd over the network, so I know the external drive would be readable, but I'm not sure about writable. Would it have to be formatted from my mac? Actually I'm not even sure out of the box would the external drive already be formatted or would it require a format before copying my data over?