[Too]

http://en.wikipedia.org/wiki/Vector_monitor

TLDR: Imagine a CRT/Osciloscope not sweeping row by row but instead line by line, where line doesn't necessarily mean horizontal but can be diagonal and even turn midway.

[andrewflnr]

Revised: you'll never kill the pixel unless you have a display as good as or better than current pixel displays that doesn't use them. ;)