For UK residents, like myself, OnLive has just been made available to us.
OnLive is a cloud based gaming service which allows you to play games on your TV without having to buy the high end kit needed to get the best gaming experience. Everything is done on OnLive's servers and the data is just sent to you via an internet connection. You get a complete HD experience but obviously with something like this you will need a very good internet connection with ping as low as it can be.
It's a new way of gaming which may change the way we play our computer games. However, with the average internet connection being around 8MBPS download, I can't see cloud based gaming doing that well. Hopefully as the UK goes through the digital transition, upgrading hardware all around the country, a lot more things will end up becoming cloud based.