Nokia N8 is good camera phone. I'm not sure about its speed and usability of its OS, but it takes very good photos. Can you believe it uses nearly the same sized sensor as GRDI just packed with 12MP? It sounds horrible, but it's actually better than most of existing camera phone sensors!
On the other hand, I understand the popularity of iP4 camera. I saw many pictures from it and it's impressive camera phone! Aside the limited controls and to my taste oversaturated colors, its noise reduction approach is exactly what I would like to see in Ricoh cameras. It performs mainly color noise reduction with no or very little luminance NR. The images look noisy even at low ISO, but thanks to this, they are full of details! I may be mad, but I like the sky full of noise (grain)?
I owned the iPhone 3G and although its camera was nearly rubbish, it allowed me to take some very nice photos. If the money would be no problem, I would buy the iP4 right away. Not because it's iPhone, but because its camera!