The iPhone 4 features a vastly superior display resolution (614400 pixels) over previous iPhone models, containing quadruple the 153600-pixel display of the iPhone 3GS. The screen is the same physical size, so those extra dots are used for additional detail — twice the detail horizontally, and twice vertically. For developers only using Apple’s user interface elements, most of the work is already done for you.

The past couple of days I’ve been turning the internet upside down in search for screenshots of the new interface to see how Apple “solved” the problems you get when you need to design an interface that has the same DPI as paper (here’s the best screenshot gallery I could find). Here’s a list of tricks and techniques I learned so far. Over time we’ll see more design conventions, but for now it’s just a lot of guesswork.