Great deal, still £56 online. Tesco mobile section at Bradley Stoke in Bristol had the 1000mAh for £5, the 2000mAh for £8.50 and this version 4000mAh for £13.
Comes with tips for all mini/micro usb, nokia phones and apple products and a service for free tips if not in the box. Charge two items at once. Great for our iphone and san francisco phones.http://www.energizerpowerpacks.com/us/products/xp4001/
Proper reduced tags from £56 to £13 so it is probably nationwide. They had loads left, reciept below.