Example microcache configuration

gistfile1.txt

## Declare cache zone.
fastcgi_cache_path /opt/local/var/cache/nginx levels=1:2 keys_zone=microcache:5m max_size=1G;

map $http_cookie $no_cache {
   default 0;
   ~_mcnc 1;
}  

server {

	listen	80;
	server_name local.domain.co.uk;

	access_log	/opt/local/var/log/nginx/domain.co.uk.access.log;
	error_log	/opt/local/var/log/nginx/domain.co.uk.error.log debug;

	rewrite_log on;
	root	/data/local.domain.co.uk/app_emorsgateseeds/webroot;
	index	index.php index.html index.htm;

	client_max_body_size 20m;

	# Not found this on disk? 
	# Feed to CakePHP for further processing! 
        location / {
            try_files $uri $uri/ /index.php?url=$uri;
        }

        ## This kind of config is "insecure" a bad habit from Apache that gets propagated on Nginx. 
        ## Try location = /index.php and see if it works.
	location ~ \.php$ {
		fastcgi_read_timeout 200;
		fastcgi_pass 127.0.0.1:9000;
		fastcgi_index index.php;
		fastcgi_intercept_errors on; # to support 404s for PHP files not found
		fastcgi_param  SCRIPT_FILENAME $document_root$fastcgi_script_name;
		
		include		   /opt/local/etc/nginx/fastcgi_params;
		
		fastcgi_cache	microcache;
		fastcgi_cache_bypass $no_cache;
                fastcgi_no_cache $no_cache;
		fastcgi_cache_key $scheme$host$request_method$request_uri;
		fastcgi_cache_valid	  200 302  1h;
		fastcgi_cache_valid	  301	   1d;
		fastcgi_cache_valid	  any	   1m;
		fastcgi_cache_use_stale updating error timeout invalid_header http_500;
	}

	# Static files.
	# Set expire headers, Turn off access log.
        ## Do you need a regex here? Can't you use an exact location? = /favicon.ico?
	location ~* \favicon.ico$ {
		access_log off;
		expires 1d;
		add_header Cache-Control public;
	}
	location ~ ^/(?:img|js|css|cjs|ccss)/ {
		access_log off;
		expires max;
		add_header Cache-Control public;
	}

	# Deny access to .htaccess files,
	# git & svn repositories, etc
        location ~ /\.(?:ht|git|svn) {
		deny  all;
	}
}

How to cache a mobile version of my site if i'm using the same url for both?