language selection

hi everyone,

i have a family blog that is used by users in germany, the states and finnland. however not everyone knows english, so i would like to ‘locaize’ the ‘backend’.

what do i mean?

well i figure if i insert a php scrip in the wp-lang section

define (‘WPLANG’, ‘en_US’);

then i could adjust the ‘backend’, the part where the users are creating the blogs (write, manage, comment, edit,…) according to their computer setting.

i imagine it would be possible with uploading the relevant language files in the wplang folder.
then changing the above define line to something reading out the computer setting (this is my poor attempt now to script it in php):
define (‘WPLANG’, <php? select language from IP address, use this language to pick translation pack, if it does not exist use en_US php?>);
everyone logging in now or registering would see the ‘backend’ in his/her preferred language.

i know that the theme needs to be localized as well, but this would be a concern at a much later point. mainly i want to ensure that users know what to do to upload picutres, write blogs, create categories and so on.

merry x-mas,
evert