We regularly cover iPhone apps for business and marketing, but we’re not oblivious to the lighter side of the platform.  We’re actually pretty amazed at how a simple – and often trivial – app can be the hottest commodity on iTunes with the right angle.

Take for example the Pirate Talk iPhone app.  This application translates your words and phrases into pirate speak.   It comes preloaded with 180 pirate one-liners (”a doubloon to the man who brings me his head!”) and offers definitions for common pirate terms.  The best part?  This is an audio app.  Just tap on the iPhone’s screen to launch a pirate translator.

Pirate Talk is as mindless and as fun as any application out there, but it has something extra going for it.  Tomorrow, September 19th, is International Talk like a Pirate Day. It’s no coincidence that the latest version of the application was released a week before the holiday.

The idea here is to target a special day, perhaps even an event, when creating an iPhone app.  It doesn’t need a flashy interface or a bunch of moving parts and pieces – just a good theme to help promote it.  For all the scalawags and geeks out there, $.99 is a small price to pay for a bit of amusement.

Unfortunately, I can’t pull the audio from my iPhone, so you can’t hear my “Read Feed Growth or Die! Yaar!” battle cry, but you can watch the app in action below.