When I first started working with CodeIgniter, not using GET really threw me off as well. But then I realized that you can simulate GET parameters by manipulating the URI using the built-in URI Class. It’s fantastic and it makes your URLs look better.
Or if you really need GETs working you can put this into your controller:
parse_str($_SERVER['QUERY_STRING'], $_GET);
Which will put the variables back into the GET array.