I'm so glad when googling i found this site to find that it's not just me that is constantly hammering my brain in regards to which iPhone colour to get!?
The main two points for me in regards to both are:-
Black: Showing up greasy smudges and finger prints
White: If the white border is going to distract from the screen
Currently i have a white iPhone 3G so am prob ready to upgrade to iPhone 4. My 3G is white and i love the fact that it stands out and also hides the smudges and finger prints on the back. I have really grown attached to my phone since jailbreaking and would sorts feel sad to let it go as i think the phone is brilliant.
My only concerns are A) the fact that my current supplier O2 as gone from unlimited data usage to a cap of 500mb (also cut mins from 600 to 300 and charging 20p for MMS now) for same monthly price.
B) If i do change i will want to keep the phone for some time so the colour, although only cosmetic is important to me to make the right choice.
In Depth:-
Covering my main concern is the contrast of the screen. Will watching say a movie or youtube clip or even browsin the internet become a concern when the front is white?
Aswell as the fact that the white border stands out more, also if you look closely even on the black one you can see a thin band of black where the screen has no active pixels, this blends in more with the black but may be a constant niggle on the white.