Currently the formats mp3 and ogg are supported and the applet is finding and playing the music files automatically. All you need is the link to the torrent containing the music and use a browser that has Java enabled. It works very well if the torrent has a lot of seeders but you can run into troubles with torrents that have only a few.
The first parts of the file are prioritized during the streaming to make sure that you can listen to the music as soon as possible. I personally think that this is an interesting concept that will surely find some users who will love it. It's probably great if you want to preview a album or song before you download it.
Update: The web service is still available, and works as advertised. Just copy the torrent url into the form and click on Play afterwards to start playing the music as soon as enough of it has been downloaded.
The developers of the service have created an experimental video streaming applet that can be used to stream torrent videos directly on a web page. For that to work, the videos need to be in Ogg Theora format. Examples are provided at the Bitlet website.
Please note that the service requires that you have the Java plugin installed in your web browser, as it won't work otherwise. You can download the latest version of Java from the official download page over at Oracle.
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.