Google Currency Conversion
Google has a currency conversion feature built in to its search, all you have to do is search for 100 GBP in USD, for example, to convert £100 (UK Pounds Sterling) to US Dollars. If you don't know the acronym for the currency you're converting to then don't worry as you can also do conversions with a search like 100 USD in Czech money, if you were planning a trip to the Czech Republic.
