I just started playing the Pirates of the Carribean online RPG and its pretty cool. It requires a minor download and there is a watered down free version. After playing it the last 2 days I think I'm upgrading to full membership when I have the money. For roughly 80 bucks I can buy a full years membership. They have a 6 month deal as well and I think normally its like 10 a month.
Anyway as for gameplay its pretty cool. Combats easy to learn and its like a basic version of World of Warcraft. The game of course also features ship battles. You can buy bigger and better ships and you even get to name them. My current ships named Shadow Raven. You can even have crew members abouard your ship and join or start guilds. The main characters also appear in the game. In the beginning you break out of jail with Jack Sparrow.
Long story short check out the game if you like its free to play. Although the free version is watered down it will give you an idea of how the game works. If your not looking to play seriously and just want to take a peek at it who cares if its not the full game.