A common way to format titles (of movies, songs, publications,...) in English is to capitalize the starting letter of every word (for example: The Hitchhiker's Guide to the Galaxy).
This practice popular in the current Italian too, but is it accepted by the grammar or is just a recent influence from foreign cultures? In this case
Guida galattica per gli autostoppisti
Guida Galattica per gli Autostoppisti