I've never seen this before
http://www.argos.co.uk/static/Product/partNumber/9820999/Trail/C$cip%3D1500011159.Garden,%2BDIY%2Band%2Bleisure%3EC$Brands%3DPhilips.Philips.htm
Cos lets face it, so many plugs are weird shapes, with power bricks as they are, they don't always fit onto the long solid ones.
Expensive...but clever.