I've never used Lighttpd, but here's the configuration file---or, more precisely, the directives that are relevant to NNF---I'm using with nginx. Maybe someone will find this useful.

%
http {

  charset        utf-8;
  charset_types  text/css;

  gzip             on;
  gzip_buffers     16 8k;
  gzip_comp_level  1;
  gzip_disable     "msie6";
  gzip_types       application/rss+xml
                   application/x-javascript
                   application/x-font-ttf
                   application/xml
                   font/opentype
                   text/css
                   text/plain
                   text/xml
                   image/svg+xml;
  gzip_vary        on;

  index  index.php index.html;


  server {
    set  $root  NoNonsenseForum;
    
    listen       80;
    server_name  forum.your-website.com;
    root         $root;

    location / {
      # pagination
      rewrite  ^/:(\d+)$ /?page=  last;

      # sub-forum
      rewrite  ^/((?:[^\./&]+/)+)(?::(\d+))?$ /?path=&page=  last;

      # thread
      rewrite  ^/((?:[^\./&]+/)*)([_a-z0-9-]+)(?::(\d+))?$ /thread.php?path=&file=&page=  last;
    }

    location ~* \.ico$ {
      expires  1w;
    }

    location = /favicon.ico {
      try_files  $uri  /favicon.default.ico;
    }

    location = /apple-touch-icon.ico {
      try_files  $uri  /apple-touch-icon.default.ico;
    }

    location = /apple-touch-icon-precomposed.ico {
      try_files  $uri  /apple-touch-icon.default.ico;
    }

    location ~* \.(?:xml|rss)$ {
      add_header  Expires        "Sun, 01 Jan 2012 00:00:00 GMT";
      add_header  Cache-Control  "max-age=0, must-revalidate, no-cache, no-store";
    }

    location ~ index\.xml$ {
      types {
        application/rss+xml  xml;
      }
    }

    location ~* \.(?:gif|jpe?g|png)$ {
      expires  1M;
    }

    location ~* \.(?:ttf|woff)$ {
      expires  1y;
    }

    location ~ /\. {
      deny  all;
    }

    location = /users {
      deny  all;
    }
  }

}
%