IBM Japan and Sanyo are teaming up to bring a real fuel cell system to notebook PCs in the near future. Sanyo has already developed a hybrid battery system with both standard lithium ion battery and fuel cell which can be used on existing ThinkPad models. Said system uses a 130cc cartridge, leading to about 8 hours of battery life. The best part, though, is hot-swapping fuel cell cartridges for uninterrupted mobile computing. The worst part? It weighs 2.2kg (nearly 5 pounds).