Hi Max : I get over stretching the colied cable of the wristband by having a multiple socket strip, on a lead from the wall socket, in England these are very cheap from Ikea. The soldering Iron and powers supply go into two of the free sockests leaving me with two other sockets for wristband and antistatic mat.
@Duane: In most US wall sockets, the screw that holds the outlet plate on is grounded. If that's the case, you could just connect to that screw for your earth ground.
But they I still have the probem that the wall socket is quite a way from the table -- unless I attach a loong piece of wire -- and I don;t fancy attaching and detaching that wire each time I want to play with my electronics...
Just to be sure, I ran it past a couple of my ESD experts here.
Connect your ohm meter between the ground wire you have coming out of that USB cable, and the ground pin on the AC power plug (with the AC power cord unplugged). If it's less than 1 ohm, you're good to go.
You might not actually be connected to ground. You have DC going from the power supply to the notebook. Depending on how the power supply is isolated or not isolated, grounded or not grounded, there may not be a direct connection to an earth ground.