Seafood Watch Pocket and iPhone Guides
California's Monterey Bay Aquarium created several simple ways to keep track of which fish are in short supply with their newly updated pocket guides and iPhone application.
Ideal for chefs or anyone with a conscientious mind, the geographically-organized maps help users source local fish and provide great alternatives to fish that should be avoided. They've also included a useful sushi guide, which like the standard seafood guide has a search function that also sorts by best ranking.
The application and pocket guides are free, along with a wealth of information on ocean and overfishing issues from the aquarium's website.