The other answers seem to be good, from what I read. However, I just wanted to put in my two cents based on my experience.
A little water has never seemed to hurt any plant I've tried it on. It should help a little. How hard the sun is shining, and how clay-like your soil is, should influence whether it's worth it. If the sun isn't out, go ahead. If it is, it'll probably dry up fast, but I don't think it will hurt at all, whether or not it helps. If the water sinks through the soil easily, a little water should be better than if it doesn't.
You can always shade the plants after the small amount of water to make it last a little longer, but if they're sun-loving, I don't recommend doing this a lot.
I have found, however, that when using small amounts of water, my plants seem to prefer filtered water over the regular chlorinated city water. It seems to perk the plants up more with less water (at least the tomatoes I tried it on). However, we had leaves over the soil to keep it moist (although that increased our cutworm-like problem, I think). Those tomatoes didn't require much watering. They weren't in full sun, either, but they still produced well for how long they had been growing. They were a hard, pasty tomato that sliced well, grown from a store-bought one that wasn't pasty (marketed as either roma or baja, I believe).
Covering the ground with something safe for your plants may help to reduce the watering needs. Black plastic is somewhat helpful there, and helps to control weeds. Leaves may be good, but they may increase insects and such in the soil, as well as mold and whatever else.