What if you had a Mophie-like battery pack for your MacBook? Available for preorder now, the BatteryBox is exactly that.
The box itself is about the length of a credit card and packs a whopping 12,000mAh battery. That equates to about 12 hours of extra juice for the MacBook Air and 6 hours for the Pro. The BatteryBox can charge any device over USB, and it has its own MagSafe2 connector.