[xwiki-users] Cache optimization

Hello all, I am running Xwiki with Tomcat 6.0.14. I noticed using firebug that lots of the images are not cached. This really slows down loading the pages in the wiki. Same goes for some pages with lots of contents. How it's possible to specify the cache policy for the xwiki concerning some pages and images. Is it possible also to have a cache policy for the whole wiki. I read that tomcat doesn't have a cache policy so it depends on the browser more or less to chose what to cache and what not to. Any hits or ideas about that? Cheers