Marc Edwards of Bjango, and co-host of our Iterate podcast, has put up some pro tips and tricks on exporting iPhone, iPad, and other UI elements from Photoshop.
It’s probably the least interesting part of designing software, usually entailing hours of grinding. Saving images to multiple scales — as required by iOS and other platforms — adds complication to the process. However, there are ways to streamline or automate exporting.
Check out Marc's article, linked below, so you can get your pixel perfect apps and web sites out of Photoshop and into the hands of users.