[WillAdams]

leebase, the human eye can resolve much finer than 300 dpi --- 400 dpi is where fonts start to look nice on a laserprinter and imagesetters are easily differentiated by their output at 1,270 ppi vice 2,540 ppi (and there are models which go higher) --- see the book _Counterpunch: Making Type in the 16th Century, Designing Typefaces Now_ by Fred Smeijers for electron micrographs and a discussion of this.

Granted, the iPhone screen is 326 _pixels_ per inch, so one gets anti-aliasing, yielding a higher effective dpi, but screens need to get better yet.