There's the 40V phidget, but it would be great if there was a 80V version of it.
For controlling power, using the relays are great but it would be more ideal if they had a barrel jack input on one side connected to the common and the NO/NC on the other. that way it can help get around the need for any soldering or splicing of wires when setting up a test fixture.
Products for USB Sensing and Control
