Thought I'd chime in with a note/tip - just be careful when implementing all this solely via .htaccess. If you have VPS or dedicated server you may already have some of the optimisations configured and setup directly via httpd.conf or httpd.conf include files (i.e. in whm/cpanel) which is the more optimal way of implementing these optimisations.
More online tools and tests for you to check your progress posted on my personal blog at
http://vbtechsupport.com/388/
HTH
George