Karl Courtney ran a pirate-themed restaurant, but at some point flipped out, believing there were three men who shared the role of Batmen, and that they were his three brothers. So he became a full-on pirate-themed villain, determined to get back at his Batmen brothers. Interestingly, in 1976, almost 20 years before Speed, Captain Stingaree's plan began by planting a bomb in Commissioner Gordon's car that would explode if he dropped below 50mph. I think Keanu Reeves owes Captain Stingaree some royalty money. There's a loving tribute to a later issue (which I've never read) in Captain Stingaree's introductory arc over here.
Pros: Did you hear about that new pirate movie? It's rated "Arr!" That's the best joke ever. And with, I think, no more Pirates of the Caribbean movies coming, a Captain Stingaree appearance would give me new opportunities to use that awesome joke.
Cons: Those three movies probably exhausted the public's appetite for pirates for a good while.
How I'd do it: Bruce and Lucius use the high tech boys at Wayne Enterprises to make a seriously high tech 19th century sailing ship, and Batman hits the high seas on the Bat-Clipper, headed to the Barbary coast. Does that still exist?
After The Scarecrow, Ra's Al Ghul, The Joker, and Two-Face, who should be Batman's next enemy in the Batman Begins/The Dark Knight series? Well, as of now we know that Tom Hardy will play Bane and Anne Hathaway will play Catwoman.
Check out the master list for all the villains covered. I've pretty much run out by now. Obviously, there are more Batman villains, but not any of significance that I know of. As of February 2009, no one is confirmed as a villain. Not the Johnny Depp Riddler, not Phillip Seymour Hoffman Penguin, nobody.