If you have a laptop or other big device, it will probably be taken out and x-rayed seperatly. if you have a cd player, they'll probably notice it and move on. the wires and everything else, you might want to check that
. nervous people, and well, yeah, check anything that is electrical in nature and that you won't need on the plane (except if it's valuble and fragile).
also, about the 70 lbs thing, that was for a checked bag, and they said we'd have to pay like $50 more if it's over 70 lbs.