Your post requires I write a book to give you all the answers needed.
So you will have to do some work yourself by reading as much as possible about these subjects first.
Then simply have a go and if you get stuck on a specific then please feel free to ask for help.
BTW in the php.ini file, you only need to uncomment this:
;extension=php_memcache.dll
to this - delete the semicolon
;
extension=php_memcache.dll
Save the file and restart Apache to have those edits recognized but always remember to make a backup of any ini or conf file before editing.
The correct php.ini file is located here:
xampp\apache\bin\php.ini
Check that memcache is now active by going to:
http://localhost/xampp/phpinfo.php
or from the menu in the XAMPP Welcome page.
Here are some links to some reading to start you off:
http://us2.php.net/memcache
http://www.google.com/search?q=memcache
http://www.danga.com/memcached/
is there a way I can view my localhost on the internet?
Localhost is not viewable from the Internet, thats why it is named as it is.
You can however, using a virtual host configuration, set up your XAMPP installation to access both the XAMPP Welcome pages and your intended danga site or indeed what ever else you wish to serve to the Internet.
Again some reading will make achieving this much quicker.
Read the file
xampp\apache\conf\extra\httpd-vhosts.conf file
Do a search in the
XAMPP for Windows Forum using the Category
Apache Friends In English, both accessible from the drop menus in the Search Options section and use the keyword vhost or virtualhost etc.
There are many links to info in the returned search results that will help you get started.
Please don't hesitate to post back if you get stuck after having a go at all this.
Good luck.