The (most recent) iPods can read documents in their Notes folder in Czech, Danish, Dutch, English, Finnish, French, German, Greek (modern), Hungarian, Italian, Japanese, Korean, Norwegian, Polish, Portuguese, Russian, Simplified Chinese, Spanish, Swedish, Traditional Chinese, Turkish, Bulgarian, Croatian, Romanian, Serbian, Slovak, Slovenian and Ukrainian. They must, however, be in Plain Text (not .rtf or .doc or html).

For single-page notes (4KB or less), make sure they are encoded in MacRoman (for English and W. European languages) or UTF-16 (for any language). This can be done via the "save as" dialogue of TextEdit.

For longer documents, use the Mac program Book2Pod, which breaks texts up into 4KB pages with links backward and forward at the top and bottom of each page:

http://www.tomsci.com/book2pod/

For languages other than English, convert your text to UTF-8 before processing. This can be done via the "save as" dialogue of TextEdit. Also choose UTF-8 in the encoding button of Book2Pod.

The basic references for iPod notes can be found here:

http://developer.apple.com/hardware/ipod/ipodnotereader.pdf
http://docs.info.apple.com/article.html?artnum=61894