I like the idea of Coinchoose, the idea is excellent, being able to compare different coins for profitablity.
However, I think we should have one for real currencies! Line up Euros, CAD, USD, Yen... All the major currencies, and see how they are relative to each other, same way we can see how cryptocurrencies are relative to each other.
The main use I can think this would be good for is exchanging currencies. I know one of the great thing about bitcoins is the ease of transfering money across borders, buy turning CAD to BTC to Euro (for example). So, if we had a comparison chart (like coinchoose!) we could see what the best exchanges would be!
I'm no programmer, so I'd have no idea how to implement this, but if the guy who runs coinchoose sees this... I'm sure it wouldn't be too hard to copy the code and have it watch real currencies instead of cryptos