chinty, take a look at the example PHP I just put together for you at http://twitch.apiexampl.es/
http://twitch.apiexampl.es/gameimg.php?game=minecraft <- To see the example for results for minecraft
http://twitch.apiexampl.es/gameimg.php.txt <- To see the source code.
Then to elaborate on your request, about the game specific to you, I wrote
http://twitch.apiexampl.es/gametag.php?streamer=NAME
again, you can see the source at http://twitch.apiexampl.es/gametag.php.txt
Then I made a modified version of gameimg specifically to show you a working example using gametag.php
http://twitch.apiexampl.es/chinty.php
source: http://twitch.apiexampl.es/chinty.php.txt
(For the example I set the streamer to jcarverpoker since it was the current most popular stream online)
I apologize for the lack of comments in the code, I will get around to commenting it later. If you have any questions just shoot me a message.
The gametag.php bit could run in 1 single .php file with everything else, I just separated it for the example.