PHP RSS XML newsreader

Hi all,
I hope someone can help,
I've made an RSS xml newsreader in flash that reads rss files from syndicated news sites, but a lot of these companies get a bit upset if you access the feed too often.
What I'm hoping someone has is a small php script that will goto "whatever" site every 30 mins and make a copy os the rss file to the local server where my site is hosted.
All I need the php script to do is make a copy of it, not parse it.
Thanks in advance if you can help.
Andrew

every 30 minutes? if you are on a *nix box,...just setup a cronjob to wget that file every 30 min,...

if you on win32,....I dunno,...lol

Well, you can also use fsockopen() to grab and read the file - write the file out to the server that is using the feed - and then create a script that does checking on the filemtime(). So, using filemtime(), you can check the last inode change or creation time and do a little math on the returned timestamp to instruct the script whether to use the file on the server, or grab a fresh copy of it. That will even cut down more of the load as it will only query the other server when needed instead of automatically every 30 minutes.