Three days, many miles and about 12 candy shops later, we're back, dusted free of sand, and once again wearing clothes that don't smell like a salt marsh. Based on our whirlwind and no doubt incomplete trip to Tillamook, Cannon Beach, and Seaside, I feel confident recommending the following:
Go to the Aquarium in Seaside, even though it looks (and is) a little cheesy and perhaps overpriced. It's basically two big rooms on the bottom floor of some sort of hotel, but buying $1 servings of chopped up fish (served in little french fry containers) and feeding them to the seals is a real treat. The seals are very dog-like; they have figured out the system and what people like to see (little encouraging nods, fin slapping) and their shiny eyes and slippery bodies are tremendously cute. Also know that when the sign says "splash zone" they are not kidding.
Spend as much time as you can in Cannon Beach and maybe don't even bother much with the other towns. There are lots of lovely shops including a very nice quilt shop, an indie book store, and (much to Aspen's liking) a candy store on about every block. Mostly, though, it's just so beautiful and charming. All these little clapboard houses and not a fast food place or huge Super 8 sign anywhere in sight. We lucked into a last-minute deal at a guest house that would be worth staying in for the bathtub alone.... huge, beautiful, overlooking the estuary. For once, no one needed to be strong-armed into getting cleaned up (if only there was a fancy sink that had the same effect on getting children to brush their teeth without reminders...).
Go outside whenever there is a break from the rain and/or wind and soak up the wonderfulness of new beaches and big white waves. Get your pants wet and then admit to your mother that you only packed one pair of jeans because "you can wear jeans for two days in a row". Make formerly white socks look an unrecognizable color. Work up an appetite. Demand food every hour and a half and get hot cocoa with whipped cream for every meal. Do not let a single piece of fruit cross your lips. Stay up late and watch programs like Dancing With the Stars and Glee that you don't get to watch at home.
Ah, vacations. :)