Sky ran this offer a few months ago and it's a cracking deal if you are considering Multiroom / Multiscreen
Sky Multiscreen offers the ultimate flexibility to watch the TV you love in and out of the home. Upgrade now and watch on the big screen in another room with a free Sky HD Multiscreen box and free standard setup*. Plus, enjoy popular shows and movies^ on your compatible devices and download them to watch anywhere, even without an internet connection.
The contract is for 12 months, but you can cancel at the end of the 12 months (or rather 31 days before), if you wish:-
12 months half price Multiscreen offer: £5.60 extra per month for 12 months (then £11.25 extra a month) for your Multiscreen subscription. You will continue to receive the Multiscreen subscription at £11.25 extra a month unless you give 31 days' notice to cancel.
£30 Cashback via Quidco