We have something like that at Blogdrake.net See http://mdktrans.blogdrake.net/index.php
It's based on SimplePo, with some customization (I didn't do it, so I can't tell you which things has being changed). We pick PO files, and put them at http://mdktrans.blogdrake.net/index.php There, MDKTrans members log in and translate lines. Other members come after, and check. When it's ready 100%, Diego Bello (MDKTrans coordinator) uploads PO file again to Mandriva server. Cheers! tavillo1980
