What's the ideal accessory for the great British summer? An umbrella of course, with this Vodafone Booster Brolly also being a little useful in the mobile department too.It's designed for festivals and will be launched at the Isle of Wight festival later this month, although as a concept in partnership with University College London, it's unlikely to be on the shelves for a while.Get your hands on one at that festival and it will keep you dry, obviously. But it's not just about keeping the rain away. The carbon-fibre handle packs an eco-friendly mobile phone charger, which is powered by 12 lightweight solar cells built into the double-layered canopy. Which essentially means it will charge a smartphone battery in under three hours via USB.Those same panels also power a micro antenna, which should, in theory, boost your 3G signal, and as a little bonus, there's also an LED torch built-in. Well, you never know when you'll need one.Of course, you'll look very silly when the sun comes out, but if the rain does comes down, you'll be able to call someone and tell them all about it.