ya know, fish is meat and even though it's quite a bit wetter than other meats, it can quite successfully be made into sausages. I've been doing so for years. Smoked fish works very well, just a little egg as a binder and whatever other filler you like. There are lots of recipes out there for shrimp or lobster mousse. I've use a shrimp mousse base, added lobster or sea scallops and had awesome sausages. I don't use animal casings. Just wrap in foil and steam until done. If you want some color, fry them a bit or slide them on a cookie sheet and put under a broiler. BTW when their done steaming, unwrap them carefully and drain off any residual liquid. That liquid, reduced with a bit of white wine and butter is to die for.

I live in Alaska and love to fish. I have a freezer full of halibut & salmon and am always looking for ways to use them creatively, I would love to see some fish sausage recipes if any turn up. Not quite a sausage, but i have had great success imparting all sorts of flavors into fish balls (especially Halibut) and would be happy to share recipes and techniques if your interested. I do also question Mr_vittles answer as smoked salmon is cured in a salt/sugar mixture without degrading the flesh.

Chanterelle's signature dish is seafood sausage. Chanterelle is a much mourned restaurant in Manhattan. You can probably find seafood sausage recipe in The Chanterelle Cookbook.

pierino - That seems like a terribly narrow-minded answer. Fish sausages are traditional in some Asian cuisines, I'm just wondering why it is so uncommon in other areas. I suspect it has more to do with the lack of fat and the ease with which it overcooks, but I was hoping to get something more concrete. Thanks all for your input.
PS. Rick Bayless/Topolobampo does a fish chorizo, but that's an new recipe.

http://gulffishing.com/cg931.html

http://www.cooks.com/rec/doc/0,1923,159186-248192,00.html

Personally, I've never encountered it in Italy (nor Spain). It's possible to do a lot with fish, but stuffing it into another animal's intestinal lining is a little baffling. I suspect we have them to satisfy the low-cal, fat-phobic whims of silly American shoppers who can afford swordfish bangers.

I am not sure if fish sausage exists in a any incarnations in Europe (possibly Northern Europe in Scandinavian countries), but I may know why it would not be very common. Sausage is essentially a cured meat. Salting ground meat and encasing it in animal intestines. Fish muscles/ meat is primarily water, like all meats, but to more of a degree than terrestrial animals. This high level of water content, may impede the ability to add enough salt, to draw out enough moisture to make it stuff-able (also making it too salty). Fish meat is also very delicate and forcing it through a grinding machine would probably turn it into a smoothie (not to mention what would happen when you actually stuffed it into its casing). I am sure if you tried making sausage out of a dried form of fish, say salt cod, it could be done. All of this is my opinion and could very well be wrong, so take it with a grain of salt.