Petside.com published this list of the top ten beaches in the U.S. for dogs:
1. Cape San Blas (Port St. Joe, Florida)
2. Quiet Waters Park (Annapolis, Maryland)
3. Block Island (Rhode Island)
4. Cannon Beach (Cannon Beach, Oregon)
5. Fort De Soto Park (St. Petersburg, Florida)
6. Carmel City Beach (Carmel, California)
7. Jekyll Island (Georgia)
8. Coronado (San Diego)
9. Stewart Beach (Galveston, Texas)
10. Montrose Dog Beach (Chicago)
Personally, I'd add Fire Island, where my Aussies Duey (pictured) and Elbee spend their summers waiting for me to toss the ball. The seldom-enforced leash laws aren't enough to keep Fire Island off the list, though the significant lack of tourist infrastructure is.