Well, you could always just size up one of those heated blankets, and attach it to the wall. Maybe even combine it with a more efficient fuel source like Natural Gas, and heat water that flows through the system instead of a coil. Sounds much more efficient, especially if you have multiple people in your household. Imagine a system like that...
I was attempting to be srcastic and explain that mounting a radiator on a wall connected to a gas boiler would be an improvement on what we have here. Also, many places in the UK and Ireland have insulation on exterior walls already.