(I'm calling this #2 because I'm going to consider the 40 hour computer battery post #1)
A JET PACK that works for more than a few seconds. There are a few drawbacks (like needing a plane to get it to the proper altitude), but still it is incredibly cool. It's a little too flashy for Quinn, but I can so see this in the next Bond film.
WIRED has more details.
Take a look...the real flying starts about a minute thirty to a minute forty-five in: