Yelp.com features a vast catalogue of user-uploaded menus for many of its listed restaurants. Allmenus.com is another service that has an extensive library of menus for restaurants, delis, and take-out establishments in major U.S. cities.
Most of the menus uploaded to Yelp come from user pictures or scans from physical copies of menus or take-out fliers from restaurants. Users should keep in mind that the restaurant may have changed or updated its menu since the Yelp user uploaded the scan. Yelp is also a resource for reviews of restaurants from users and bloggers.
Allmenus.com features a library of menus submitted directly by restaurant owners, and is more likely to be up-to-date.