The only elegant way I can think of to solve the toasting non-uniformity problem requires a breakthrough in materials science. If you could make the toaster's

The only elegant way I can think of to solve the toasting non-uniformity problem requires a breakthrough in materials science. If you could make the toaster's heating coils out of a substance that increases its resistance with increased light influx, then the bright areas of the toast would increase the coil resistance nearby, thereby producing more heat locally and tending to even out the toast. Of course, this is probably a lot of work just to make a toaster.