other things to consider:

     # if you compiled --with-http_spdy_module
     listen 443 ssl spdy;

     # amusing how many of these you'll get
     location ~*\.php {
       add_header "Not Found" 404;
     }

     # pretty sure you need to do this to have keepalive working
     # between nginx and the upstream
     proxy_set_header Connection "";
     proxy_http_version 1.1;

     # buffer writes to disk (for a busy site, you can use much larger values than 1K)
     access_log /var/log/nginx/access.log buffer=1K;

     # cache the ssl connction parameters
     ssl_session_cache shared:SSL:20m;
     ssl_session_timeout 10m;