Can someone speak to the Lumia 900 "ClearBlack" finish? I suspect this is where I've gotten it wrong about my phone.
What did you want to know about it?
Basically it works similar to the way that polarized sunglasses can help you see on a sunny day out on the water, by cutting the reflected light.
On a screen without ClearBlack, sunlight, glare etc will hit the phone screen, then reflect back in your eyes. So you see a reflection of the sky and the clouds, or you get your office lights reflecting back at you. This is especially noticeable in black areas of the screen. The usual response to this, is for people to turn up the brightness of the screen and hopefully it gets bright enough to overpower most of the reflected light.
With ClearBlack, which is a special type of polarizing filter, the light from the sun, or your indoor lights still hits the phone's screen, but it is deflected away from your eyes so you only see the light coming from the phone's screen itself, the light you WANT to see. So you don't need to make the screen nearly as bright to be able to see things very clearly. That saves battery life and just makes the phone generally nicer to deal with, especially outside in the sun.
The special filter combined with an OLED type screen where the pixels are actually "off" and not giving off any light when they are displaying black, gives you a very nice result. Basically black areas on the screen appear very dark and the screen doesn't allow outside light coming in to water down the colors or obscure your view. The end result is, a picture or a web pages, or whatever you are looking at looks exactly the way it should whether you are standing outside in the sun, or inside under harsh florescent lighting, next to a campfire or in a darkened room.
This link has a little illustration and explanation too:
Nokia reveals polarizing secrets of ClearBlack display -- Engadget