A few minutes ago I got an email from some friends who are planning to come to London for a visit this summer. My friend was asking about currency rates saying that he heard they were pretty bad (they are).
I pointed him to the currency calculator on Google, and gave him a couple of sample queries to get him started. For example he wanted to know what the exchange rate was for the £, that query is "1 GBP in USD", he also wanted to know the same for Paris, "1 EUR in USD".
I use these tools all the time for expense reports and vacation planning,