I recently switched to the new, incredibly thin Macbook 12". Aside from it's portability and fanless design, the promise of powering it via USB-C from a portable battery managed to convert me from a loyal Macbook Pro user. Unfortunately, there aren't many 29W battery packs on the market, and much to my disappointment, the in-seat USB ports on airplanes doesn't have a strong enough current either.
Enter Voltus - an elegantly designed external battery that offers either 9 or 13 hours of extra power, in addition to 2 extra USB 3.0 ports. Personally, I can't wait to get my hands on one.