The problem we had with buying a whole bunch of backup laptop batteries for CES and liveblogging was that we could only charge them inside the laptops themselves. This means waking up in the middle of the night and swapping batteries, which totally ruins snuggling time with Travis and Mark. With NewerTech's MacBook and MacBok Pro battery charger, we can sleep soundly through the entire night and wake up with two refreshed batteries in the morning and still be snug in that Gizmodo sandwich.
The charger has two slots, one that chargers and conditions and the other just charges, and will work on both stock and aftermarket MacBook/MacBook Pro batteries. At a price of $149, it's not cheap, but definitely worth the price if you need it.
Product Page [NewerTech]