I just thought of unethical ways to do the Pligg translation: this is what we did for Portuguese translation(the client is OK with sharing the translations - good guys do exist) (will share it sooner - as some parts are pending)
1]
Use Google translator:
http://translate.google.com/translate_t to translate from English to desired language
2]
Ask others to share
If you see translated Pligg on a site, Ask the author/owner to share it - politely
3]
If tip #2 doesn't work - Steal the lang.conf from other sites 
This is the most un-ethical part. Many site owners use Pligg, translate for their need but never bother to give them back- this is a special treatment for such candidates. Just try the following to get the lang.conf:
http://sitename.com/libs/lang.conf - Bingo - you got the translated version (Beware: There is more possibility that the candidate has chosen to customize the lang for their site: example instead of "vote" - they might have "Spike it!" or some-other things - you should consult tip #1 to verify this)
Once translated - please do share here by uploading at
http://forums.pligg.com/downloads.php?do=add&cat= and paste the link as a reply in here
Done.