The MP3 file is suitable for most Android phones (Nokia, Motorola, Samsung, LG & HTC). The M4R file is specialy made for the Apple iPhone.
About this site: I've set up this site as a little experiment to see how many visitors a microsite can get. There's only one thing to do here, and that is to download this ringtone, for which there seems to be a small demand online. If you have any questions you can reach me at email@example.com (anti-spam: please remove the bird from the south pole)