Currency Pro was actually the first app I ever downloaded for my iPhone. It allows you to view a list of currencies around the world and convert any amount from one currency to the next. If you do a lot of international traveling, the app is invaluable. Now the developer has released version 3.0 which brings iPad support to the app. But instead of just making a super-sized version of the iPhone app, the iPad app introduces several cool iPad-only features.
My favorite feature of the iPad version of Currency Pro is the map. With it you can view a Google map of the world and tap on a pin to view a country's currency. Another tap will add the currency to a tracking list. At first glance, the map just seems like eye-candy, but it's actually extremely useful if you want to quickly look up a currency but don't know the name of it. For example, if you travel a lot in Europe, it's a great way to quickly check who is actually using the Euro.
The iPad version of Currency Pro also lets you quickly search lists of currencies based on content and also tracks the price of precious metals.
Currency Pro is $4.99 and an essential app for any travelers. There's a free ad-supported version of the app, simply titled Currency, which offers all the same features with the addition of an iAd.