If you dropped 1 kg (1000 g, 2.2 lbs) off the wheels, or bike, or your body, you'd get to the top of Mt Diablo 34 seconds sooner (assuming you can do the south gate from the school in about an hour).

Are new wheels worth that? If I was racing it and had the money, maybe. For training or riding for fun? Not really.
It is of course worth losing the weight from your body unless you're so thin that losing more would make you slower. Not many people are in danger of that.

"rotational inertia" difference of wheels exist, but is so small it is not a factor. Especially on climbs where there's no significant accelleration.

edit: 1 lb (454g) would be 16 seconds. Not sure what I was thinking using 1kg- that's a lot for wheels.