This plugin clean your titles (post slugs) looking it as MT does (putting '_' instead '-', killing the dots on decimal numbers and sanitizing -not deleting- non-english characters). Great support for non-english languages. E.g. before "Ya está por salir Mozilla 1.7", after "ya_esta_por_salir_mozilla_17".
Just download, unzip, upload to wp-content/plugins/, login and activate it... that's all, folks!
The plugin support characters of many languages, like: spanish, catalan, gallego, french, portuguese, dutch, german, etc.
Please, let me know about your use of it or any improvement you do :)