I'm looking getting a 15" PB in the near future as a portable desktop replacement. Will it be able to: -run my scanner (a cannon lide 30) which is powered through its USB cable? -run multiple external drives (can I connect 2 or 3 external HD's to a USB hub and then connect the hub to the PB?) -run both of those items and an external monitor at the same time, while plugged in (I've read that PB's need to be plugged in to power an external monitor)? I'm sure I'll come up with a couple more, but those are a good start.