The power supply for my Mac Laptop gets nice and warm and at
this exact moment I have it pushed down behind my back, held in
place by the belt on my jeans, whilst transmitting its wonderful
heat into my aching lower lumber region.
I have done this because I managed to reactivate a back strain
week, whilst dragging a heavy sofa across the floor.
The power supply operates at the perfect temperature to provide
relief, but it lacks two important features which would be easily
implemented to make it absolutely perfect.
Item one: a very slightly more ergonomic shape, achieved by a
slightly convex/concave profile modification.
Item two: the addition of a simple vibration mode.