For example you can change background and theme, overclock it(maybe not a good thing if this is needed), the im integration(I really LOVE the msn/skype/facebook chat). The screen is better in one way but I can go 50/50 here as iphone screen is more responsive. The keyboard is a big plus as it wont block half screen while typing.

And just such a thing that n900 is much better out of the box means a lot. But why do you think iphone is better? Iphone might have much more apps but for me the important thing is not how many apps it have. It's about the regular dayly use such as internet, multitasking, music and IM. And of those its only music that is better at the iphone

But it is true that a lot of people hate the phone because it is a apple on it, if nokia would have done it, it would be loved... Iphone have many good sides but I am not that iphone person