After going through several generations of battery types, we seem to have settled on Lithium-Ion. You're finding them everywhere, and manufacturers are letting their young engineers loose to play.
Milwaukee and DeWalt offer inverters that can replace a small portable generator -- using your power tool batteries. No noise, no fumes, no fuel, and safely, conveniently stored in your house.
Makita has released a coffee maker and a microwave -- again, using the batteries you already have. Not to mention a full line of lawn care equipment.
Job site lighting has never been better.
IcyBreeze sells a battery powered air conditioner (NOT a swamp cooler) that you'll love the next time you're in a cramped panel room making connections. Look it up.
I wonder what they'll come up with tomorrow.