The built-in contact manager does not support the fields for the furigana (phonetical transcription) for the names in other non alphabetical languages (expecially Japanese and Chinese). The vCard standard supports these fields and it should be implemented in the built-in conctact manager.

One possible solution is to implement the two furigana fields, and use them for sorting the contacts in alphabetical mode.

In addition to it a sorting for kana (japanese phonetic alphabet) fields should be implemented.

Vote here:
http://maemo.org/community/brainstor...i-in_contacts/

I made a little research about furigana fields and discovered that in vCard they are stored in an extension with the values:

X-PHONETIC-FIRST-NAME:
X-PHONETIC-LAST-NAME:

Giving as a result a file like:

BEGIN:VCARD
VERSION:3.0
N;CHARSET=SHIFT_JIS:姓 名;;;;
FN;CHARSET=SHIFT_JIS:姓 名
SORT-STRING;CHARSET=SHIFT_JIS:ｾｲﾒｲ
X-PHONETIC-FIRST-NAME:
X-PHONETIC-LAST-NAME:
...
END:VCARD

You may want to focus this suggestion on the Community SSU, as that seems to be where the majority of new features will be coming from.

I am not sure where to find the sources for the address book program (at least, not on gitorious) so locating those would be a first step.

Sorry for the quite stupid question but, what is the Community SSU and where can I find it?

Maemo5 uses Evolution-Data-Server as its backend for contacts, hence the proper way would be to implement this in e-d-s first.
That's why you've filed https://bugzilla.gnome.org/show_bug.cgi?id=640203 .

Basically Maemo5 will not receive new features as it is considered stable by Nokia and future development happens on meego.com.
There are also community efforts to provide Maemo5 updates ("Community SSU").