Callista Currency Converter is probably the most convenient currency converter around, it is free and has no ads!
Just enter an amount, press return, and the amount will be converted to all the currencies you have selected.
Use it full screen for easy access when you are travelling or use it snapped when you are browsing foreign web sites and quickly need to convert amounts to your currency.
Converts between the 72 most commonly used world currencies. AED, ARS, AUD, BAM, BDT, BGN, BRL, BYR, BZD, CAD, CHF, CLP, CNY, COP, CRC, CZK, DKK, DOP, DZD, EGP, EUR, FJD, GEL, GBP, GTQ, HKD, HRK, HUF, IDR, ILS, INR, IQD, IRR, ISK, JMD, JOD, JPY, KES, KRW, KWD, KZT, LTL, LYD, MAD, MUR, MXN, MYR, NGN, NOK, NPR, NZD, PAB, PEN, PHP, PKR, PLN, RON, RSD, RUB, SAR, SEK, SGD, SYP, THB, TND, TRY, TWD, UAH, USD, VEF, VND and ZAR.
Additionally any of the supported currencies can be converted to and from Bitcoin.