Spotify Unlimited streams music advertisement-free for £5 per month. You can use the new sharing features that integrate Spotify with Facebook and Twitter, and play your MP3s through the same interface as the streamed music. The £10 Spotify Premium option is unchanged -- the extra fiver buys you offline playback and an app for iPhone and Android phones.
Spotify Open is available to everyone and gives you free access to the full catalogue, but with ads and a limit of 20 hours listening per month. To get unlimited listening, you'll need an invite from an existing user. Spotify's aim is to manage the bandwidth used while getting as many people as possible trying the service -- Facebook integration is spreading the word on walls around the world, and membership is available with new phones such as the Sony Ericsson Xperia X10 and Vivaz on 3.
Is a fiver enough to tempt you into paying for Spotify? Are you a Premium user who's going to downgrade? Sing us your song in the comments. If you're after an invite, we have a few going spare to the first ten lucky commenters. Register your email address when you leave your comment but don't write your email in the comment box -- you might be spammed. Tell us your favourite song instead.