I always found very difficult to design mockups for iphone while you are on photoshop, because of proportions reasons. Even if a 640x960px document in photoshop is large enough to work on every details, it’s always quite a surprise to see the same document opened on an iphone (using jpg exportation and the native image viewer of the iphone) : font size can look very small, global proportions can look wrong, … (more…)