It doesn’t have anything to do with the narrowness or the contrast of the font (which you called refered to as “sharpness” ) and it has everything to do with the fact that nokia sans is simply ugly.

“The curviness of “Century Gothic” [Very similar to "Prelude", used in Palm Pre I think] is often found in children’s books because of the emphasis on classic alphabet shapes and thus readability.”

Wrong. You should refer to latin fonts as “classics”. Century gothic is designed in 1991! It’s a modern 20th century font based on Futura, another 20th century font. Futura is used in education simply because it’s a geometric typeface thus easy to get accustomed to for kids that age.

“Prelude is probably the best font at the moment being used on phones. The letters are very curved, a little more readable than Century Gothic (E.G. letter r), but less wasteful on character spacing.”

Although I agree that nokia needs to fix their typography, you should also seek further information before deciding to share your subjective opinions about readability or typography in general. Still, nice post.

True also on theme changing – most people aren’t aware of it.