The upcoming annual Strawberry Festival in Arroyo Grande is a great place to go with kids. This occurs on the Saturday and Sunday of Memorial Day Weekend (but not on Monday.) The Strawberry Festival is one giant mass of vendors hawing sunglasses, garden knicknacks, clothing, jewelry, perfumes, olive oils, soaps, hats, t-shirts, dog and pet gear, wallets, shoes, posters etc etc etc. And then there is the food - lots of it. And the constant music by local groups and bands, playing at various venues throughout the town center. (All of the downtown is closed to cars - this is where the vendors set up.)
And then there are the strawberries. Arroyo Grande actually still grows strawberries, but the entire crop (and then some) must be used up this one weekend. Multiple vendors sell strawberries in every conceivable preparation - with whipped cream, on pancakes, with ice cream (note the line out the door of very popular Doc Burnstein's Ice Cream), as smoothies, or all of the above mixed together.
At the end of few hours there, you and the kids will leave tired and happy, full after having inevitably given in to eating one of the Strawberry Concoctions, and loaded down with souvenirs that you never knew you needed until you got there. And the kids will have never once proclaimed "I'm bored.". Enjoy!