Childcare for kids in school when school's not in session

For those of you with school-age kids (so they're not in daycare anymore), what do you do with your kids when school's out for the summer in terms of childcare?

In NYC, most people put their kids in some kind of daycamp, which can range from affordable to crazy expensive, depending on the camp, neighborhood, etc. Camps start filling up in March or April for school to be out in mid-June (private schools) or late June (public schools).

What's the situation where you live? Is it affordable? How easy is it to sign up?