Don't have an iphone5 yet... Generally I only drive black cars and use black phones; it looks sexier, more powerful, conveys authority and respect. I like to be taken serious perceive a "powerful" image... I LOVE driving a black car; it gets dirty fast but I feel "powerful" driving it, like people take me seriously and give me more respect. It's probably all in my head but as long as it makes me "feel" that way then why not?
However, from what I've been reading black iphone5 shows scratches faster which is the only reason why I am leaning towards white... however, aesthetically black looks better.
Look at Presidents and Prime Ministers; do they drive white cars? No, they always get chauffeured in black cars because it looks more "official" and "prestigious". I want to be taken seriously. Nothing looks more powerful than a black Benz or BMW.... However, I don't want a scratched up iphone so I still have to consider white...