Despite all this open-source chest-beating and puffery, how do you know one way or another whether there are or aren't secret codes (these codes or otherwise)? How can you even say that there aren't any if you can't look over the source code?
these codes are not secret.
they where invented so that people can get info like IMEI number out of Serise40 phones that didnt have any user interface other than dailing.
at least the *#06# one is officially published in nokia developer site (i remember i saw it there), so the developer gan sign his test applications.
and although the N900 can reveal that information in several other ways (e.g. the about screen in settings) the code seems to work too.
