I'm moving PirateWalla to an in-app purchase model so that I can make the base level free, and still continue to be somewhat exclusive about who gets to find the cool items (By charging for the item location feature I can make sure that those who have paid for this feature still have lots of cool items to find that haven't been plundered by freeloaders).  One of the reasons I want the base level of PirateWalla to be free is because I'm planning to add Game Center integration (with high scores!).  Basically the way I look at it is:

Want to compete and see your high score?  -- Free

Want an edge and the ability to find items you are missing? -- $5

Sadly, Apple left me no route to migrate my existing users to the new application ( See the explanation here:  http://blog.logichigh.com/2011/05/26/converting-applications-to-in-app-purchase/ ).

However, I plan to the best I can and offer all the new search functionality for .99 for a limited time (so that all existing users can get the feature at the cheap price), and then drop the price of the app and return the price of the item location feature to the $5 mark.

This has been started.