thomasdawes, hadn't thought about one for the home and one for the office. A very good reason, saves carrying a brick. (but does't fit my more mercenary-like work assignments)
Divine_madcat
Li-ion is ok, but modern rechargables (e.g. NiMH) can put an awfull lot of energy in a small space while allowing 1000+ recharges. I'm not even using the best ones with 850mAh in a single AAA, compared with Acer's 4800mAh in my standard battery.
OK, there's a bit more to it, I am sure, but still.
hth
Drio