InstaClass is a simple PHP-class for communicating with the Instagram API.

1. Create a client at http://instagr.am/developer/clients/register/
2. initialize the class with your client id and client secret
<?php
        require_once 'instaClass.php';
        $clientId = 'YOUR_CLIENT_ID';
        $clientSecret = 'YOUR_CLIENT_SECRET';
        $config = array(
            'redirectURI'   =>  'http://www.yourdomain.com/'
        );
        $instagram = new instaClass($clientId, $clientSecret, '', '', $config);
        $SAVE_THIS_CODE = $instagram->authenticate();
        print $instagram->getError();
?>
3. Take the authCode received from the part above, and request a token:
<?php
        require_once 'instaClass.php';
        $clientId = 'YOUR_CLIENT_ID';
        $clientSecret = 'YOUR_CLIENT_SECRET';
        $authCode = 'AUTHCODE_RECEIVED_IN_STEP_2';
        $config = array(
            'redirectURI'   =>  'http://www.stilero.com/'
        );
        $instagram = new instaClass($clientId, $clientSecret, $authCode, '', $config);
        $SAVE_THIS_TOKEN = $instagram->requestAccessToken();
        print $instagram->getError();
?>
4. Proceed with the calls to the Instagram API
<?php
        require_once 'instaClass.php';
        $clientId = 'YOUR_CLIENT_ID';
        $clientSecret = 'YOUR_CLIENT_SECRET';
        $authCode = 'YOUR_AUTHCODE_FROM_STEP_2';
        $accessToken = 'TOKEN_FROM_STEP_3';
        $config = array(
            'redirectURI'   =>  'http://www.stilero.com/'
        );
        $instagram = new instaClass($clientId, $clientSecret, $authCode, $accessToken, $config);
        //Get the 20 most recent images from authenticated user
        $images = $instagram->recentUserImages();
        foreach ($images as $image) {
            print '<img src="'.$image['full'].'" />';
        }
        print $instagram->getError();
?>