Hey guys. So I have a MacBook Pro with Snow Leopard, and I am looking to buy a large external harddrive (1+ TB) to back up my computer with (using Time Machine). Can I do this wirelessly, even though I do not have Airport Extreme or the Apple external harddrive (I will most likely buy a Western Digital or some other big-name brand). Also, my family PC is running Windows XP. Is a way I can wirelessly back up that computer as well to this external harddrive, or will I need to plug that in to the PC. Finally, can I back up both a Mac and a PC on the same harddrive? Thanks in advance guys. I really appreciate it.