Instructions:Found in the insert to the TRON Legacy Blu-Ray, £30 off any of the following HP ePrint printers:
Photosmart Plus (CN216B)
Photosmart Premium (CN503B)
Photosmart Premium with Fax (CQ521B)
Photosmart eStation (CQ140B)
Voucher code is valid at Amazon.co.uk, and according to the leaflet also on Tesco Direct and HP's online store.
Bought myself the Photosmart Plus from Amazon, £45 with super save delivery, and Amazon throw in a USB cable for free :)