Since a lot of you asked me how to convert the fonts to be usable on the iPhone, here it is: a very quick how-to.
The fonts are TTFs, optimized for small size (they lack a lot of info, I guess some crossplatform stuff that Mac OS X does not need). There are two versions, the ones in
/System/Fonts (original, unmodified TTFs, with copyright intact) and the ones in
/System/Fonts/Cache (optimized for size and minimal info).
Files and font names are mapped in
CGFontCache.plist, which is a binary plist; it can be decompiled and edited with various tools; in Windows the easiest way is with
Total Commander and
T-PoT.
The system seems to accept any font, optimized or not, it's just not aware of it until it's mapped correctly in CGFontCache.plist). You can add fonts which will show up on the various applications (book readers for example) by adding them to that plist.
For the UI and Safari fonts you need some tools to change the internal font names, though. I use FontLab 5 to copy font information from the original fonts. After opening both original and my custom font, I use
Copy... from
Font Info to sync font names, styles and font identification. Some fonts need slight adjustments to Ascent/Descent values to look OK on the iPhone. Generate, replace originals.
You can also copy/paste only some glyphs from custom to originals.
If the UI crashes, you still have access to the filesystem and can undo anything (if you bothered to make backups, that is; did you?).
Very simple stuff, really. Knock yourselves out.
