Is there a unit converter for the Nokia N900 that can convert imperial to metric? Specifically I need one that is useful for cooking with measures like teaspoon, tablespoon and cup in it (I got given a very nice cookbook as a gift but all the measurements are American and useless to me here in Australia)

If there isn't one, I will look into writing my own but no point reinventing the wheel if one already exists (or if one exists that does conversions but doesn't support the units I need, I can add features to that one instead)