Grooveshark's music service is web-based and easy to navigate, and you can be listening to music you like within seconds of opening the site. You don't even need to log in - you can just search for a song and play it. The search even autocompletes with popular artists and songs.
If you do log in, you can save playlists of other people's songs or upload your own. You can also follow other users and comment on their playlists.
There may be questions about Grooveshark's legality, but it insists it is doing nothing wrong, and is paying artists for the use of their songs.
With OnLive, cloud gaming is a reality. The service requires no discs, hard drive space or high-end components, enabling you to play on devices such as laptops and tablets.
The grunt comes from OnLive's servers, which it upgrades every month with the latest graphics cards and extra RAM. Basically, you play remotely via the internet.
Press a button and the command is sent to the OnLive servers, which interpret the command and send pictures to your screen showing the result. If you have a good broadband connection, your gameplay should be lag-free.
Read our full OnLive review
Do you remember the days of making a mixtape (or even CD) for your friends with a special note or image in it? Well, 8tracks has taken that premise online.
Positioning itself as a hand-crafted radio station, 8tracks enables you to upload or search for the music you like to create compilations at least 30 minutes long (or about eight tracks' worth).
You can then add a description and pictures to your compilation and share it with other 8tracks users, who can rate and comment on your mix.
Deezer is another music site well worth tuning into. It's been around in the US for a while and already has over 20 million users, but it plans to open its 13 million licensed tracks up to 130 more countries, including the UK.
Deezer is determined to be a legitimate, licensed music site, supporting musicians and others who earn a living from music. It's easy to dismiss as just another streaming service, but it has big plans.
Deezer's founders feel that MP3s have robbed people of the feeling of browsing your shelves and listening to complete albums, and want to restore the lost art of music curation to the masses.