A new and improved version of Vodafone's massively mobile multiple handset recharger is being rolled out just in time for thousands of festival-goers to all hold up their phones to record the same Black Keys performance. The revamped truck still does that whole charging 2,000 phones at once thing, but adds DJ booths and new hand scanners to help phone owners more efficiently retrieve their gadgets, when it comes time to check into Foursquare -- you don't want someone else to become the mayor of the chillout tent, a