Buy one of three's mobile internet dongles - or mifi, and they give you spotify premium for 3 months. I guess so you use loads of bandwidth....
Anyway Spotify premium is normally £10/month,
x3 = £30 for 3 months,
and the cheapest dongle is £20,
so a saving of £10 and a free dongle.
T and C from three website:
3 Months Free Spotify Premium on Mobile Broadband.
Offer available to customers registering and connecting a new mobile broadband connection (Pay As You Go or Pay Monthly) from Three in September and October 2010. No additional data allowance included in offer, music streaming will use your normal allowance. 1GB of data will give approximately 14 hours of listening at the default settings of the Spotify Application. At the end of the free period customers can opt in to continue paying for Spotify Premium at £9.99 per month. To redeem go to http://www.three.co.uk/freespotify
when connected over mobile broadband and enter the phone number associated with your mobile broadband sim card. An existing Spotify Premium account cannot be converted to free for the period of the promotion. Customers can either upgrade an existing Spotify Open subscription to premium or create a new account. Offer closes 30/11/2010.