Is there an officially sanctioned API for google calculator? alt text http://img717.imageshack.us/img717/6815/calcu.png
According to http://code.google.com/p/cl-gcalc/ there is no officially sanctioned API for google calculator and, having done some digging around, that really is the general consensus.
I found http://www.dynamicguru.com/php/currency-conversion-using-php-and-google-calculator-api/ which seems to think there is an API for Google calculator, though this just used the calculator page and things which are included on the calculator help page