A lot of portable PC power cells last for only four or five hours, after which you'll find yourself chained to a wall socket. Good thing there are external batteries to keep us in current when a plug's nowhere to be found, and Tom's Hardware has done some benchmarking on a slew of such devices so you'll know which one's suited for you. A Dell Vostro 3300 and an Inspiron Mini 10 running Windows 7 were used to put packs from Amstron, Brunton, Digipower, Electrovaya,
