Blue crabs are smaller than Dungeness and instead of being served with butter and lemon, they are steamed with a hell of a lot of Old Bay seasoning and eaten as is. The result is a sticky, spicy, salty experience that is alot of work, but worth the picking.
We ordered a dozen mediums (that's what they recommended for two! they are quite small- about the size of a man's hand), bought a couple mallets (they don't use crackers) and dug in over a couple bottles of ginger beer. It was messy, fun and delicious, but we both concluded that we prefer the west coast's dungeness and find the seasoning a bit too salty. Next time we'll see if they'll steam them half seasoned for us.