noaa.govからmetarを取ってきてim.kayac.com経由でiPhoneにプッシュ配信する例。cronで数分おきに発火させてます。

metartoimkayac.php

<?php
//noaaからmetarを取得する
function push_metar($airport,$username){
	$airport=strtoupper($airport);
	$old_filename="metars/${airport}.old";
	$metar=file_get_contents("http://weather.noaa.gov/pub/data/observations/metar/stations/${airport}.TXT");
	$old_metar=@file_get_contents($old_filename);
	if(strcmp($metar,$old_metar)!=0){
		file_put_contents($old_filename, $metar);
		$data=array("message"=>$metar);
		$data = http_build_query($data, "", "&");
		$header = array(
		    "Content-Type: application/x-www-form-urlencoded",
		    "Content-Length: ".strlen($data)
		);

		$context = array(
		    "http" => array(
		        "method"  => "POST",
		        "header"  => implode("\r\n", $header),
		        "content" => $data
		    )
		);

		$url = "http://im.kayac.com/api/post/${username}";
		return file_get_contents($url, false, stream_context_create($context));
	}else{
		$result=json_encode(array("id"=>"","error"=>"duplicate","result"=>"not posted"));
		return $result;
	}
}
echo push_metar(ICAO,USERNAME);
?>