I would just like to warn you about ordering shellfish in a restaurant. I'd read in Anthony Bourdain's book that he recommends you only eat mussels from a person you trust. I didn't really believe him at the time; but now I do. I've had two experiences where I've eaten clams or mussels in reputable restaurants and gotten sick. Not just slightly ill, but pukey and overcome with nausea.
I think the reason is that it's very easy to serve bad shellfish. Normally, when you cook at home the cardinal rule is that you discard any clams/mussels that do not open after you cook them because this signals that they were dead before you even placed them in the steamer/saucepan, etc (and for who knows how long.) But in a restaurant setting; obviously, it is to their financial benefit to pry them open and serve them.
Also, in Mr. Bourdain's book he mentions that you should never eat seafood on a Monday. He says that it's impossible for a restaurant to get seafood delivered from their suppliers on a Sunday; so what you're eating are the leftovers from the weekend. Again, this potentially compromises the freshness of seafood.
So just be careful when ordering in a restaurant! If the shellfish looks suspicious or tastes funny don't eat it!