This is a simple extension for Alfred, based on Google Currency Converter.
To use the Currency Converter, you’ll need the Alfred Powerpack. Once the extension is installed, simply type "convert X <oldcurrency> to <newcurrency>" into Alfred and let it do the rest. You’ll need to use three-letter ISO currency codes (USD, EUR, GBP…), and of course you’ll need to be connected to the Internet. This would look something like this:
Now, if you want to save some time (and hey, you’re using Alfred, so this should be right up your alley), you can shorten things up a bit by leaving away the “to” keyword, our using your keyboard’s currency symbols ($, €, £, ¥):
convert 1.234 USD GBP
convert 1.2 $ to £
convert 1.2 $ €
You can also set a default target currency in the script (default = EUR), making things even shorter:
convert 2.345 SEK
convert 2.345 $
Either way, you’ll get a nice Growl-popup with the result:
You can get the most recent version of the extension here.