Get ready for WWDC.

cron.php

<?PHP
  $html = file_get_contents('https://developer.apple.com/wwdc/');
	
	if($html === false)
	{
		send_script_failure();
		exit;
	}
	
	preg_match_all('/2012/', $html, $mentions2012);
	preg_match_all('/2013/', $html, $mentions2013);

	$mentions2012 = count($mentions2012[0]);
	$mentions2013 = count($mentions2013[0]);

	if(($mentions2012 != 3) || ($mentions2013 != 1))
	{
		send_message();
	}
	else
	{
		echo "Everything's fine.\n";
	}
	
	function send_message()
	{
		for($i = 0; $i < 5; $i++)
		{
			curl_setopt_array($ch = curl_init(), array(
			  CURLOPT_URL => "https://api.pushover.net/1/messages.json",
			  CURLOPT_POSTFIELDS => array(
			    "token" => "<token>",
			    "user" => "<user>",
			    "message" => "WWDC tickets might be on sale!",
				"sound" => "siren",
			  )));
			curl_exec($ch);
			curl_close($ch);
			sleep(5);
		}
	}
	
	function send_script_failure()
	{
		curl_setopt_array($ch = curl_init(), array(
		  CURLOPT_URL => "https://api.pushover.net/1/messages.json",
		  CURLOPT_POSTFIELDS => array(
		    "token" => "<token>",
		    "user" => "<user>",
		    "message" => "WWDC script failed.",
		  )));
		curl_exec($ch);
		curl_close($ch);
	}

@bradchoate Nice call on checking for the image filename.