http://www.onlive.co.uk/
For those of you who don't know, Onlive is one of the pioneering companies looking to develop cloud gaming. The software is still new and a touch unreliable with some users experiencing input lag and stuttering, but its worth a shot for what is an amazing introductory offer...
They have an introductory offer of getting [b]ANY[/b] game for £1 that is already released. No pre-orders here folks.
Worth a punt for £1,
Spark.