Making LCD Screens Readable in Full Sunlight?

irregular_hero asks: "I'm in the process of constructing a navigation and vehicle-management system based on Linux for a car. The trouble I'm having is finding a suitable screen to be mounted in the dash of the car. It seems that traditional SVGA/XGA LCD screens have a really bad tendency to totally wash out in bright sunlight -- in fact, nearly every screen that I've tried turns jet black in sunlight. Are there any SVGA/XGA LCD screens out there that one can get that are sunlight-readable? Or is there a way to make an existing screen not respond so badly to sunlight?"