The latest version of Griffin's TuneJuice battery pack is here in the form of TuneJuice Universal ($25), a clean little soft touch black and chrome plastic enclosure that includes the first set of three AA batteries you can use to replenish a depleted iPod or iPhone -- assuming that you supply your own USB cable. Griffin claims that TuneJuice Universal adds 2.25 hours of talk time to the iPhone 3GS, which is to say a little under half its original…
