I\'m trying to enter some UTF-8 characters into a LaTeX file in TextMate (which says its default encoding is UTF-8), but LaTeX doesn\'t seem to understand them.
Runn
A brute-force way to check the encoding might just be to check the file in a hex editor or similar. (or write a program to check) Look at the binary data in the file. The UTF-8 format is fairly easy to recognize. All ASCII characters are single bytes with values below 128 (0x80) Multibyte sequences follow the pattern shown in the wiki article
If you can find a simpler way to get a program to verify the encoding for you, that's obviously a shortcut, but if all else fails, this would do the trick.