I have an airline power adapter that would let me use my laptop at my seat during a flight without worrying about running out of battery. The only problem is that you can't always get a seat that has power at it.
Enter the "Inflight Power Recharger".
It lets you plug into the audio jack at your seat and use that to charge your USB-enabled device (Ipod, MP3 player, cell phone, etc.). Yes, it won't do the laptop...but heck, if I can watch my Ipod Video during an entire 10 hour international flight without worrying about its battery...I'm game!