On my travels as a contractor, I've seen various methods used for embedding fonts in ActionScript 3 projects (code embedded, creating font SWFs, runtime loading, etc). Each of them has its own merits (and limitations), but generally you're looking for something that's easy to do, easy to maintain (for others, not just yourself) and of course that works!
So, here's the method I use for pure AS3 projects I compile with the Flex SDK. I embed the TTF or OTF file in a 'Style' class and include those font files in the CVS/SVN repository too - it does my head in when fonts go missing, because a designer can't remember which font they used:
import flash.text.TextFormat;
// UNICODE RANGE REFERENCE
/*
Default ranges
U+0020-U+0040, // Punctuation, Numbers
U+0041-U+005A, // Upper-Case A-Z
U+005B-U+0060, // Punctuation and Symbols
U+0061-U+007A, // Lower-Case a-z
U+007B-U+007E, // Punctuation and Symbols
Extended ranges (if multi-lingual required)
U+0080-U+00FF, // Latin I
U+0100-U+017F, // Latin Extended A
U+0400-U+04FF, // Cyrillic
U+0370-U+03FF, // Greek
U+1E00-U+1EFF, // Latin Extended Additional
*/
[Embed(source = '../fonts/myfont.ttf', fontName = 'MY_FONT',
fontWeight = 'regular', unicodeRange =
'U+0020-U+0040,U+0041-U+005A,U+005B-U+0060,U+0061-U+007A,U+007B-U+007E',
mimeType = 'application/x-font')]
public static const MY_FONT :Class;
public static const DEFAULT_FONT :String = "MY_FONT";
public static const DEFAULT_TEXT_COLOUR :int = 0xFFFFFF;
public static const DEFAULT_TEXT_SIZE :int = 14;
public static const MY_TEXT_FORMAT :TextFormat = new
TextFormat(DEFAULT_FONT, DEFAULT_TEXT_SIZE, DEFAULT_TEXT_COLOUR);
Through experience, this seems to be the most robust and maintainable way of dealing with fonts (not to throw out more flexible, but perhaps less robust ways, such as runtime loading), especially when you need control of the unicode ranges you are embedding - which I have included for reference.
